Here are some of the changes to the House bill unveiled Wednesday night.

Massie had a fairly memorable line on the House floor earlier tonight with respect to how this bill could affect the nation’s deficit: “We’re not rearranging deck chairs on the Titanic tonight. We’re putting coal in the boiler and setting a course for the iceberg.”

Mr. Trump established the commission in February to examine what he called the “growing health crisis in America.” But he asked the panel to begin by looking at chronic disease in children.

Mr. Kennedy has repeatedly said that the United States is suffering from an epidemic of chronic disease that is particularly acute in children, citing the rising incidences of autism and attention deficit hyperactivity disorder.

“To fully address the growing health crisis in America, we must re-direct our national focus,” the executive order establishing the commission declared, adding, “This includes fresh thinking on nutrition, physical activity, healthy lifestyles, over-reliance on medication and treatments, the effects of new technological habits, environmental impacts, and food and drug quality and safety.”

The executive order paints an especially dark picture of Americans’ health. It notes, for instance, that the United States had the highest incidence rate of cancer in 2021 out of 204 countries and territories, and has experienced an “88 percent increase in cancer” since 1990. But it does not note that death rates for cancer have been steadily declining in the United States.

Among other instructions, the order directs the commission to examine harms it suggests are caused by antidepressants and electromagnetic radiation.

The order does not mention two factors that the Centers for Disease Control and Prevention lists as the main causes of chronic disease: smoking and excessive alcohol use. The Trump administration is shuttering the C.D.C.’s Office on Smoking and Health, and has fired the top tobacco regulator at the Food and Drug Administration.

Mr. Kennedy has previously blamed ultra-processed foods, which are expected to feature heavily in the report, as a major cause of chronic diseases in the United States, and has promised to “fix our food supply.”

But administration actions in the last few months have in some cases contradicted that goal. In March, the Agriculture Department abruptly ended a program that provided produce from local farms to schools. Scientists at Harvard and Cornell have lost funding for research aiming to improve the diets of children and teens. And Kevin Hall, a researcher who led some of the most highly cited studies on ultra-processed foods, left the National Institutes of Health in April, citing censorship.

The report is being spearheaded by Calley Means, who is a special adviser to the White House on health issues and a Kennedy ally. The commission is composed of cabinet secretaries and top federal health officials, including the heads of the C.D.C., the F.D.A. and the N.I.H.

The panel’s report has been generating pushback even before its release. Some Republican lawmakers and industry representatives complained this week about the report’s expected focus on widely used agricultural chemicals, including glyphosate, the key ingredient in an herbicide marketed as Roundup.

When Mr. Kennedy testified on Tuesday before members of the Senate Appropriations Committee, Senator Cindy Hyde-Smith, Republican of Mississippi, warned him and the commission to not to insinuate that the agricultural chemical is unsafe or responsible for childhood disease because doing so could greatly damage farmers. She referred to scientific studies, including an assessment from the Environmental Protection Agency that found the chemical safe when used as directed.

“I trust your report will be described as an initial assessment of things to be considered but yet to be determined,” the senator said. Mr. Kennedy assured her that he understood that farmers rely on glyphosate and “we are not going to do anything to jeopardize that business model.”

Alice Callahan contributed reporting.

Apparently, though, endowing the accounts with the name of President Trump’s political movement was not clear enough. As part of a series of last-minute changes House Republicans made to their broad fiscal package Wednesday night, they decided to just cut to the chase. The money would now be deposited in a “Trump account.”

Under the bill, children born between Jan., 1, 2025, and Jan. 1, 2029, would receive the money, which would be invested on their behalf in financial markets. Once they had grown up, they could withdraw the proceeds to pay for certain expenses, including going to college or buying a house. The child’s parents, or other third parties, could also contribute to the account.

While the benefit of the $1,000 initial investment from the government is clear, the accounts have otherwise puzzled tax experts. People could only contribute post-tax income to the accounts, and gains in the accounts would also be taxed when money was withdrawn. That would appear to make the “Trump account” function much like a typical investment account, rather than a tax-advantaged account like an individual retirement account or a health savings account.

Here are a few of the changes:

• Republicans raised the limit on the state and local tax deduction by $10,000, reflecting a key demand from a small group of lawmakers from New York, New Jersey and California. The amendment would set the cap at $40,000 instead of $30,000. The size of the deduction would shrink for people making more than $500,000 a year, rather than the $400,000 level included under the previous version of the bill.

• An even faster phaseout of existing tax credits for low-carbon electricity has been added to the bill. Under the new language, companies building solar-, wind-, geothermal- or battery-powered plants can claim the credit only if they start construction within 60 days of the bill being signed into law and then put the plant in service by the end of 2028. That’s a narrow window that many projects will struggle to meet. There’s an exception for nuclear power: A company building a new nuclear reactor can still claim a significant tax break as long as it starts construction by the end of 2028.

• A provision was removed that would have sold off 500,000 acres of public land in Utah and Nevada. The measure was strongly opposed by Representative Ryan Zinke of Montana, who was interior secretary during President Trump’s first term.

• The date was pushed up for when Medicaid work requirements will be put in place from Jan. 1, 2029, to “not later than December 31, 2026.” States also have the option to select an earlier date to add requirements.

• Around $12 billion in funds were added to the bill that would be used to reimburse states for money spent on border security after the inauguration of President Joseph R. Biden Jr. in 2021. The legislation already included $175 billion in new spending to enforce President Trump’s immigration and detention policy, a measure that was meant to entice Republicans to vote for the package despite other cuts.

• A ban on the use of Medicaid funds for gender transition measures like puberty blockers, hormones and surgical procedures was expanded to include adults, not just children and teenagers.

But when the news reached the Department of Homeland Security, it set off a dayslong scramble and clashes among officials in three different agencies over how to deal with what everyone knew had been an error. As it became clear that keeping it quiet was not an option, D.H.S. officials floated a series of ideas to control the story that raised alarms among Justice Department lawyers on the case.

In the days before the government’s error became public, D.H.S. officials discussed trying to portray Mr. Abrego Garcia as a “leader” of the violent street gang MS-13, even though they could find no evidence to support the claim. They considered ways to nullify the original order that barred his deportation to El Salvador. They sought to downplay the danger he might face in one of that country’s most notorious prisons.

And in the end, a senior Justice Department lawyer, Erez Reuveni, who counseled bringing Mr. Abrego Garcia back to the United States, was fired for what Attorney General Pam Bondi said was a failure to “zealously advocate on behalf of the United States.”

Documents obtained by The New York Times laying out the debate among leading lawyers at the State, Justice and Homeland Security Departments reveal new details of the administration’s early efforts to develop a strategy for a case that has become a major test of President Trump’s mass deportation effort.

The discussions do not directly capture any conversations about the case inside the White House or at the level of the relevant cabinet secretaries. But the documents show how Trump officials, from the start, tried to keep Mr. Abrego Garcia out of the reach of the American judicial system.

To this day, Mr. Abrego Garcia remains locked up in El Salvador despite court rulings demanding that the United States work toward securing his release. And he got there in the first place through what everyone agreed was a bureaucratic slip-up.

“This was an administrative error,” James Percival, a D.H.S. official appointed by Mr. Trump, wrote to his colleagues on March 30. “(Not that we should say publicly.)”

Tricia McLaughlin, a D.H.S. spokeswoman, said in a statement that Mr. Abrego Garcia’s deportation was part of “a highly sensitive counterterrorism operation with national security implications.”

“We invoked the state secrets privilege over many of the details — of course our officials discussed what should be divulged publicly,” she added. “This just proves they are responsible public servants putting the safety of the American people first. The leakers of these emails, on the other hand, clearly do not care about public safety.”

Far-Reaching Consequences

According to the documents, administration officials realized quickly that the case had sweeping implications for Mr. Trump’s efforts to remove other immigrants from the United States and send them to a Salvadoran megaprison.

As Mr. Reuveni pointed out to the group, the case potentially “jeopardizes many far more important initiatives of the current administration.” If the government fought and lost, it could have legal repercussions, not least of which for the nearly 140 Venezuelans who were sent to the same facility under the authority of a rarely used wartime law, the Alien Enemies Act of 1798.

Ultimately, three courts — including the Supreme Court — pushed back against the White House, ordering Trump officials to at least take steps toward freeing Mr. Abrego Garcia. But Mr. Trump and some of his top aides have taken a defiant stance, insisting that Mr. Abrego Garcia will not be coming back to the United States.

The turmoil started on March 12, when Mr. Abrego Garcia was arrested as he drove home from work in Maryland, swept up as immigration agents scrambled to meet one of Mr. Trump signature promises: the biggest deportation operation in U.S. history.

Mr. Abrego Garcia had been under deportation orders, but there was a catch: In 2019, an immigration judge found that he could be deported to anywhere except El Salvador, his homeland, because his life was in danger there.

But on March 15, El Salvador is where the United States sent him, on one of three charter planes with scores of other immigrants. While Mr. Abrego Garcia was not deported under the Alien Enemies Act, he was a last-minute addition to the flights after someone in front of him was taken off the manifest.

On March 24, lawyers working with Mr. Abrego Garcia’s wife, a U.S. citizen named Jennifer Vasquez Sura, filed a lawsuit in Federal District Court in Maryland, asking Judge Paula Xinis to issue an order forcing the White House to bring her husband back.

The news of the lawsuit was received very differently at the Justice Department’s Office of Immigration Litigation, which typically handles such matters, than at D.H.S., which has been overseeing Mr. Trump’s deportation policies.

The documents obtained by The Times show correspondence among the agencies and the State Department between March 27 and March 31 — a critical early period that ended with the administration acknowledging its error in deporting Mr. Abrego Garcia, setting off a legal and political furor.

A State Department spokesperson declined to address the documents obtained by The Times, saying the agency would not “discuss internal deliberations or ongoing litigation.”

On March 28, Mr. Percival, the D.H.S. official, told his colleagues that they would be working to make sure that Mr. Abrego Garcia would not return to the United States.

“We are working to fix it so he doesn’t need to be returned to the U.S.,” he wrote. Joseph Mazzara, a Trump-appointed official serving as the top lawyer at D.H.S., concurred: “We’re also trying to keep him where he is.”

Not everyone was onboard.

Over several days, Mr. Reuveni, a Justice Department lawyer who had risen up the ranks over more than a decade with the agency, advised colleagues that they needed to return Mr. Abrego Garcia at once.

That was standard practice. Migrants wrongfully removed from the country had been brought back under both Republican and Democratic administrations — including during Mr. Trump’s first term.

One of Mr. Reuveni’s chief concerns was that Judge Xinis would not look kindly on the fact that the U.S. government was keeping someone abroad who had been wrongfully removed.

“I do not think the court will receive the suggestion it’s fine to keep him there while we sort this out with any sympathy,” he wrote. “And the longer he stays there, the more difficult it becomes for us to hold the line on this is not our own custody just paid through the El Salvadorans.”

D.H.S. officials said they wanted to solve the problem by trying to reverse the original order that should have kept Mr. Abrego Garcia from being sent to El Salvador in the first place. And they wanted to do so while he was still in Salvadoran custody.

Mr. Reuveni did not agree.

“How do we reopen his removal proceedings with him abroad?” he asked. “At that point he won’t have a valid executable order.”

“The cleanest solution,” Mr. Reuveni had said just days before, was to bring Mr. Abrego Garcia back to U.S. soil.

The P.R. Battle Ahead

State Department officials wanted to know more.

Were there any reasons, one asked, to avoid complying if Judge Xinis ordered the government to bring Mr. Abrego Garcia back?

“I cannot think of any basis for us to take the position that we can ignore such an order, nor would we,” Mr. Reuveni wrote.

Already, the government appeared to be highly alert to any possible backlash over the mistake. Mr. Percival, for instance, had asked his colleagues early on if the D.H.S. spokeswoman had been informed about the “comms implications” of the case.

Mr. Percival appeared to quickly realize that withholding the information was not tenable. A day after telling his colleagues that the government should not admit its error publicly, he reversed course and suggested the Justice Department’s response in court “would be much better if we could own that we made a mistake.”

“But I guess we need to figure out whether we’re allowed to say that…” he added.

Around the same time, officials at D.H.S. began to float the idea internally that Mr. Abrego Garcia was a leader in MS-13, a violent street gang at the center of the president’s deportation agenda.

If that were the case, it might make leaving him in El Salvador more palatable.

The only problem was that nobody seemed to know if it was true.

Mr. Percival asked other officials at one point whether they could tell Judge Xinis that Mr. Abrego Garcia was an MS-13 leader. Mr. Reuveni said that they could — but only if someone put their name to the accusation in a sworn court declaration.

Mr. Percival also wanted to say that Mr. Abrego Garcia was not in any immediate danger.

In the end, Immigration and Customs Enforcement officials backed away from the claims.

“So far I have found ‘verified member,’ which is included,” an ICE lawyer wrote to Mr. Percival. “I have not found anything indicating ‘leader,’ but I’ll keep looking.”

In a statement, a Justice Department spokesman said that Mr. Abrego Garcia “was illegally in our country and has been identified as a member of MS-13, a foreign terrorist organization, by multiple officials, including an immigration judge and an appellate board.”

Mr. Abrego Garcia has never been charged with, let alone convicted of, being a member of the gang. He has said that he came to the United States illegally more than a decade ago because he was fleeing a different gang, Barrio 18.

During his deportation proceedings in 2019, some evidence was introduced that he belonged to MS-13, but Judge Xinis has cast doubt on it, saying in a court order that the “‘evidence’ against Abrego Garcia consisted of nothing more than his Chicago Bulls hat and hoodie, and a vague, uncorroborated allegation from a confidential informant.”

In 2019, an immigration judge in Maryland had ruled that Mr. Abrego Garcia should not be sent to El Salvador at all because the gang was “targeting him and threatening him with death” over his family’s business selling pupusas.

The gang had menaced Mr. Abrego Garcia’s older brother, Cesar, and then turned its eyes on him after Cesar fled to the United States. When Mr. Abrego Garcia refused to join Barrio 18, some of its members threatened to kill him, the judge determined, prompting him to follow his brother to America.

Because of the potential danger that Mr. Abrego Garcia faced from members of Barrio 18 inside El Salvador’s Terrorism Confinement Center, or CECOT, a State Department official, James L. Bischoff, asked officials from both the Justice and Homeland Security Departments what he should advise the U.S. ambassador in San Salvador to do: Should the ambassador ask the Salvadorans to keep Mr. Abrego Garcia separate from the prison’s gang population or ask for his release?

Mr. Reuveni’s answer was clear. They needed to do both.

“We should seek to keep him from the gangs,” he wrote, “but more importantly and soonest should bring him back.”

Mr. Mazzara, the D.H.S. lawyer, told his colleagues that Kristi Noem, the homeland security secretary, had taken steps to seek Mr. Abrego Garcia’s segregation from other inmates, including members of Barrio 18. And the next day, he said the administration was still waiting for assurances from El Salvador that he was safe in the prison.

But Mr. Mazzara still seemed unconvinced that the gang was a threat to Mr. Abrego Garcia.

“Is Barrio 18 even in CECOT?” he asked.

In fact, the documents show that Mr. Bischoff had told Mr. Mazzara two days earlier that there were “many members of Barrio 18 in CECOT.”

‘We Concede the Facts’

The tensions between Mr. Reuveni and his homeland security colleagues came to a head on April 4, when he appeared for the first time in court before Judge Xinis.

“We concede the facts,” he immediately told her. “This person should — the plaintiff, Abrego Garcia — should not have been removed. That is not in dispute.”

Mr. Reuveni went on to explain that although there was a final order allowing Mr. Abrego Garcia to be deported from the United States, there was also another — known as a withholding of removal order — that was supposed to have ensured that he was not sent to El Salvador, where he might face persecution.

Judge Xinis thanked him for his candor, but said she had more questions. Mr. Abrego Garcia had been living in Maryland under the protection of the withholding order for nearly six years, so what authority, she asked, had law enforcement officials used when they took him off the streets on March 12?

“Your honor, my answer to a lot of these questions is going to be frustrating,” Mr. Reuveni replied. “I am also frustrated that I have no answers for you on a lot of these questions.”

The hearing, which took place on a Friday afternoon, ended with Judge Xinis entering an order clearly instructing the White House to bring Mr. Abrego Garcia back to the United States by no later than 11:59 p.m. that Monday night.

The order did not survive. The Supreme Court, quickly stepping in, first put it on hold and then issued an order directing the administration to “facilitate” Mr. Abrego Garcia’s release from Salvadoran custody.

By the time that order came down, however, Mr. Reuveni was already out of a job.

On Saturday, April 5, Justice Department leadership suspended — and ultimately fired — him.

“At my direction, every Department of Justice attorney is required to zealously advocate on behalf of the United States,” Ms. Bondi, the attorney general, wrote in a statement sent to The Times that day. “Any attorney who fails to abide by this direction will face consequences.”

The case has moved forward without Mr. Reuveni, who declined to be interviewed for this article. Judge Xinis has opened an inquiry into what steps the White House has taken to comply with the Supreme Court’s ruling.

Joseph A. Darrow, who is one of Mr. Reuveni’s former colleagues and left his own job in the immigration section last month, said in an interview that people in the office were “shocked and despondent” over the retribution that Mr. Reuveni faced.

Two other lawyers who worked with Mr. Reuveni also left in recent weeks, citing his firing.

“I agree with what Joe wrote in his goodbye email — this was an act of intimidation against all the attorneys who work here,” said Erin Ryan, a trial lawyer who announced her resignation on May 16 in an email.

She said it “put us in an impossible position where we have to decide between keeping this job pushing a partisan agenda, or maintaining our ethical obligation to the court and thus our bar license.

“I choose the latter.”

“These reports raise the troubling possibility that the department, and Attorney General Bondi personally, were integral to this scheme by crafting a legal justification to enable the president to circumvent the Foreign Emoluments Clause of the Constitution, federal bribery and ethics laws, and Congress in order to acquire one of the largest foreign gifts in our history,” the senators wrote, according to a copy of the letter obtained by The New York Times.

The letter was led by Senator Adam Schiff of California and was also signed by Richard J. Durbin of Illinois, Cory Booker of New Jersey, Richard Blumenthal of Connecticut, Mazie Hirono of Hawaii, Alex Padilla of California, Peter Welch of Vermont and Sheldon Whitehouse of Rhode Island.

It came as the United States formally accepted the gift of the jet, which industry executives estimated to be worth about $200 million, and which will require extensive work before it can be considered secure enough to carry Mr. Trump.

The senators questioned Ms. Bondi’s involvement given her previous work as a lobbyist who counted Qatar among her clients. Any role she played in the transfer of the plane, the senators wrote, was a “plain conflict of interest that undermines the public’s trust.”

Members of Congress from both parties have repeatedly expressed concern over the plane deal. They have said the Qataris might be trying to unduly sway Mr. Trump, that it may not be financially prudent to refit the plane with necessary security measures only to eventually transfer it out of government service and that Mr. Trump’s urgent desire for a new plane might pressure contractors to work quickly and cut corners.

Senator Chuck Schumer, Democrat of New York and the minority leader, has already targeted Ms. Bondi’s involvement, announcing that he would place holds on Justice Department nominees until Ms. Bondi explained why she approved the arrangement. The effects of his move would likely be limited, slowing nominations by requiring the Senate’s Republican majority to take procedural votes.

On Monday, Mr. Schumer introduced a bill that would essentially block the deal by barring the Pentagon from using any federal dollars to buy, modify or maintain such an aircraft for the president’s use.

Other Democratic lawmakers have also introduced nonbinding resolutions that would require the White House to seek approval before accepting the plane as a gift.

On Tuesday, the Senate unanimously passed the No Tax on Tips Act, following through on a vow made by both President Trump and former Vice President Kamala Harris to give tipped workers a tax break on gratuities. As of now, the tax break is being incorporated into the “One, Big, Beautiful” budget bill being negotiated by House Republicans, which would be effective from 2026 through 2028.

How would these changes affect food-industry workers and diners? Here’s what we’ve learned from interviews with tax lawyers, hospitality professors and industry groups:

How are restaurant employees currently taxed on tips?

The federal tax code requires that every tip be reported as income. Whether it’s a $20 bill handed to a host, a line filled in on a check or a button pressed on a keypad, employees and employers are required to track and report every cent. This applies whether each worker keeps the tips or the money is pooled and redistributed.

What counts as a tip?

In the tax code and in this legislation, the term “cash tip” applies to tips given in bills and coins, on a credit or debit card, or via the business’s electronic payment system. It has not yet been determined whether tips that go directly to a server via a service like Venmo or PayPal would qualify as cash. Service charges, which are legal in some places, are added by the business and do not count as tips.

What is the proposed change?

Under the legislation being negotiated in the House, tip income would be exempt from federal income taxes. That amount would be subtracted from reported income as an “above the line” deduction on a tax return. That would reduce how much income tax is owed. The tips would still have to be tracked and reported.

Who would get the deduction?

There is debate over who would benefit from the measure, which applies to all tipped workers in the restaurant business, including not only servers but also baristas, food delivery drivers and anyone holding out a payment screen after they have sold you food. According to government data, there are more than two million tipped restaurant workers in the United States.

How would this affect restaurant employees?

It would put more money in the pockets of tipped workers, like servers and bartenders, who interact directly with customers. Those employees would be able to deduct up to $25,000 in tips, unless they earned more than $160,000 in a year. (The amount will rise over time.)

Does this affect the tipped minimum wage?

No. The federal minimum wage is $7.25 per hour. (Many states and cities have higher ones.) Employers have been allowed to pay tipped workers just $2.13 of that sum since 1991. They can pay the lower wage only when the employee’s tips bring the total up to minimum wage. Those tips are also subject to income tax.

Would the change result in customers being asked to tip in more places?

Not necessarily. The measure applies only to employees who are “customarily” tipped, to be determined by the Treasury Department. Making tips tax-free might motivate businesses to encourage tipping, in order to retain employees who are chasing this deduction. It would be unlikely to reduce tipping prompts or the growing trend of tipping on more services.

How much of my tip goes directly to the server?

That depends on the workplace and local laws. Some restaurants allow servers to keep all their tips; others require tip pooling, which shares the money with bussers, bartenders and other staff members. This bill would not change who receives tips or how they are distributed.

Does tipping in cash make a difference?

Not for tax purposes. It does reduce a restaurant’s credit card processing fees, which are charged as a percentage of the total bill (about 2 percent to 3.5 percent of each transaction, and sometimes a 30-cent “swipe” fee). But it doesn’t leave a paper trail for the employee or employer to track, which can increase the risk of tax fraud. Some cash tips go unreported, which is considered tax evasion, but the scale of the problem has never been determined.

Would this change federal rules that prevent kitchen workers from receiving tips?

No. So-called back-of-house employees, including chefs, cooks, dishwashers and porters, cannot receive any tips unless they participate in a legal tip pool. There are federal regulations that govern tip pools, and some provisions vary state by state.

Would tips continue to count as payroll, for federal tax purposes?

Yes. In addition to withholding employee contributions for Medicare, Social Security (FICA) and unemployment, employers must pay taxes for those programs based on the employees’ total wages, which include tips.

Will employers of tipped workers continue to get a tip credit?

The tip credit, officially called the 45B tax credit, helps employers of tipped employees by reducing their tax bill. They receive a credit for a portion of the Medicare and Social Security taxes they pay on tipped wages that exceed the $7.25-an-hour federal minimum wage. The proposed legislation would expand that credit to beauty businesses like salons and spas, but the restaurant portion would stay the same.

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Speaker Mike Johnson and his deputies waged an intensive effort to win over holdouts with concessions and a final pressure campaign by Mr. Trump. But several G.O.P. lawmakers were still expressing dissatisfaction with the sprawling tax and spending cut package ahead of a vote expected around dawn.

Even after a meeting with Mr. Trump and fiscal conservatives at the White House, it was uncertain whether Mr. Johnson had the votes in hand to pass the bill. He spent Wednesday evening briefing lawmakers on a list of changes he had negotiated with a wide spectrum of factions across his conference.

They included speeding up new work requirements for Medicaid, increasing the state and local tax deduction, expanding a rollback of clean energy tax credits created by the Biden administration in the Inflation Reduction Act, and providing additional money to reimburse states for immigration enforcement efforts.

“Let me tell you something: It is truly big and beautiful,” said Representative Virginia Foxx of North Carolina, the chairwoman of the Rules Committee, echoing Mr. Trump’s effusive moniker for the bill, which Republicans have adopted as their own. “It is a clear, full-throated response to the millions of working men and women across who believe that America is due for a serious course correction.”

It was not clear whether those concessions would be enough to flip Republican opponents of the bill, whose ranks appeared to be growing on Wednesday as the negotiations dragged on, or whether they might alienate others whose votes would be needed to pass the measure.

With his razor-thin margin of control in the House, Mr. Johnson can afford to lose no more than three Republican votes on the legislation if all Democrats oppose it, as expected, and every member votes. The speaker has insisted the bill must pass before Memorial Day.

Mr. Trump has publicly called on House Republicans to pass the bill quickly. White House officials released a statement urging its immediate passage, with an implicit threat to lawmakers who opposed it.

“President Trump is committed to keeping his promises, and failure to pass this bill would be the ultimate betrayal,” said the statement from the Office of Management and Budget.

Democrats, on the other hand, denounced the measure as a disastrous package that would pay for tax cuts for the wealthy by slashing social programs that Americans depend on.

“Let’s call this what it is: theft,” said Representative Jim McGovern of Massachusetts, the top Democrat on the Rules Committee. “Stealing from those with the least to give to those with the most. It’s not just bad policy; it’s a betrayal of the American people.”

Representative Chip Roy, Republican of Texas and a ringleader of right-wing opposition to the bill, said in an interview on a conservative podcast that the deal had moved in the right direction, citing the further eliminations of the Biden-era clean energy tax credits.

But those concessions threatened to cost the measure support among more moderate lawmakers who have been fighting to preserve the energy tax breaks.

Emerging from Mr. Johnson’s office on Wednesday evening, Representative Andrew Garbarino, Republican of New York, would not commit to supporting the bill, saying, “It is not what I had hoped it would be.” He said he had informed G.O.P. leaders that they needed to “change some of the things they were thinking, because we need this energy produced.”

And Representative Andy Harris of Maryland, the chairman of the Freedom Caucus, had suggested earlier on Wednesday in an interview with Newsmax that conservatives were unhappy with concessions that Republican leaders had made to a group of blue-state Republicans to increase the limit on the state and local tax deduction, known as SALT, which is currently set at $10,000. The changes Mr. Johnson put forward on Wednesday night would raise the cap to $40,000, an increase from the $30,000 level that had been in the bill.

“Raising the SALT deduction is a bailout for Democrat governors — paid for by red states with low taxes,” Representative John W. Rose, Republican of Tennessee, wrote on social media. He declared that he was opposed to the measure “in its current form.”

Mr. Trump visited Capitol Hill on Tuesday to pressure Republicans to unify around the wide-ranging package, which would slash taxes, steer more money to the military and border security, and pay for some of it with cuts to Medicaid, food assistance, education and clean energy programs. He summoned fiscal conservatives and House G.O.P. leaders to the White House on Wednesday in a bid to lean on remaining holdouts to drop their opposition and back the bill.

The sprawling legislation would largely keep current tax rates in place, extending the 2017 tax cut while temporarily making new reductions like Mr. Trump’s campaign promises to not tax tips or overtime at the federal level.

The bill, which is expected to face substantial changes in the Senate, is a reflection of competing Republican factions with disparate priorities. A number of fiscal conservatives have demanded structural changes and cuts to Medicaid and other programs to hold down the overall cost of the bill and rein in deficits. More moderate and politically vulnerable lawmakers have sought to protect Medicaid, demanded larger tax breaks for their constituents and fought to preserve clean energy tax credits.

The legislation is projected to cause around 10 million Americans to become uninsured, according to the nonpartisan Congressional Budget Office.

Republican leaders opted against more aggressive options they had considered to cut Medicaid, bowing to more moderate Republicans, mostly from politically competitive districts, who warned that they could not accept such reductions. Mr. Trump has also opposed such cuts.

But they added a new requirement that childless adults prove they worked or volunteered 80 hours a month or qualified for an exception to enroll in Medicaid. That was initially scheduled to take effect in 2029, after the next presidential election, but the package of changes Mr. Johnson proposed on Wednesday would accelerate it to the end of 2026.

The legislation was expected to add trillions to the national debt, which is already at a level that many economists and Wall Street investors find alarming. In a preliminary analysis of an earlier version of the bill, the Congressional Budget Office estimated that the legislation would add roughly $2.3 trillion to the debt over the next decade.

In a separate analysis requested by Democrats, the budget office found that the legislation would leave the poorest Americans worse off while providing a lift to the richest. In 2027, the bottom 10 percent would lose the equivalent of 2 percent of their income largely because of the reduced benefits, while the tax cuts would provide the top 10 percent with a 4 percent increase to their income, the budget office estimated.

The self-imposed Memorial Day deadline for passage has created significant — if artificial — pressure, leading to fevered, down-to-the wire negotiations and an often nocturnal legislative schedule.

The Rules Committee began meeting at 1 a.m. on Wednesday and did not complete its action until 10:40 p.m. The vote to open floor debate on the measure came long after midnight on Thursday, and a final vote was expected later in the morning.

Democrats criticized Republicans for the scheduling, accusing them of trying to hide parts of their signature legislation from the public and push through changes while most Americans were sleeping.

“We should recess and give everyone the time needed to understand these changes,” Mr. McGovern said after the package of changes was released late Wednesday night. “This is a big deal. This is consequential. And we’re moving forward with major changes, and we’re just supposed to take your word for it.”

Maya C. Miller, Robert Jimison, Andrew Duehren and Margot Sanger-Katz contributed reporting.