Voters will elect a new Congress: House and Senate control are up for grabs

WASHINGTON — Americans are poised to elect a new Congress, with control of both chambers at stake as every seat in the House of Representatives and one-third of the Senate is up before voters on Election Day.

Every nonincumbent president since 1992 has entered office with their party controlling both chambers of Congress, but there’s no guarantee that’ll happen this year for either Kamala Harris or Donald Trump.

The stakes are high, with the Senate charged with confirming the next president’s judicial and Cabinet nominees, while the makeup of both chambers will determine the fate of the legislative agenda and key must-pass bills.

Republicans favored to win the Senate

In the Senate, Democrats currently have a 51-49 edge, but Republicans are favored to capture the majority. They’re all but guaranteed to win an open seat in ruby-red West Virginia, with Democrat-turned-independent Sen. Joe Manchin retiring.

That seat alone would be enough for the GOP to control the chamber if Trump wins the presidency, in which case Sen. JD Vance, R-Ohio, would become vice president and cast the tie-breaking vote in a 50-50 seat Senate.

If Harris wins, Republicans will need one more seat in addition to West Virginia to capture the Senate. The party is also looking to flip Democratic-held seats in the red states of Montana and Ohio, where Democratic Sens. Jon Tester and Sherrod Brown will have to again defy gravity in states that Trump is expected to win handily. They face Tim Sheehy and Bernie Moreno, respectively, both of whom the GOP is heavily invested in.

And Democrats are defending another five seats in purple states that are highly competitive at the presidential level: Sen. Bob Casey in Pennsylvania; an open seat in Michigan, where Sen. Debbie Stabenow is retiring; Sen. Tammy Baldwin in Wisconsin; an open seat in Arizona, where Democrat-turned-independent Sen. Krysten Sinema is retiring; and Sen. Jacky Rosen in Nevada.

Meanwhile, Democrats’ best hopes for capturing a Republican-held seat are in Texas, where Sen. Ted Cruz is seeking a third term, and Florida, where Sen. Rick Scott is running for a second term.

In deep-red Nebraska, the populist independent candidate Dan Osborn is polling competitively against low-profile Republican Sen. Deb Fischer in a race that could produce a surprise.

A close fight for the House

The race for the House is on a knife-edge.

Republicans currently hold a 220-212 majority, with three vacancies — two in safe blue seats, one in a safe red seat. Democrats will need to pick up just four seats in order to capture control of the House and, with it, the speaker’s gavel and chairmanships of all committees.

The battlefield is narrow. According to the Cook Political Report, there are 22 “toss-up” seats at the heart of the fight — 10 held by Democrats and 12 held by Republicans. A few dozen more seats are being hotly contested but lean toward one party.

Notably, the blue states of New York and California host 10 ultra-competitive House districts. Those two states are expected to be comfortably won by Harris at the presidential level, but Republicans are investing heavily in holding and flipping downballot seats there.

In New York, Republicans are defending four seats they flipped in 2022, propelling them to win the House majority. Those seats are held by Reps. Marc Molinaro, Mike Lawler, Anthony D’Esposito and Brandon Williams, all of whom are seeking re-election. D’Esposito’s and Williams’ districts are rated by the Cook Political Report as “lean Democrat” as the party has fielded Laura Gillen and John Mannion to try to recapture those seats. Lawler’s race is rated “lean Republican.” Meanwhile, Rep. Pat Ryan, D-N.Y., is facing a tough challenge from Republican Alison Esposito in the Hudson Valley in a race that is rated “lean Democrat.”

And in central and southern California, at least five GOP incumbents are also facing tough re-election bids.

Freshman Rep. John Duarte is facing Democrat Adam Gray in the 13th District; Rep. David Valadao has a rematch against Democrat Rudy Salas in the 22nd District; Rep. Mike Garcia is fending off a challenge from Democrat George Whitesides in the 27th District; longtime Rep. Ken Calvert is trying to hold off Democrat Will Rollins in the 41st District; and Rep. Michelle Steel is squaring off with Democrat Derek Tran in the 48th district.

Speaker Mike Johnson, R-La., and the man who wants to replace him, Minority Leader Hakeem Jeffries, D-N.Y., have spent the past weeks crisscrossing those key House battlegrounds, as well as a slew of swing districts in Pennsylvania, Michigan, Arizona, Nevada and the Pacific Northwest.

As polls opened Tuesday morning, the chair of the House Democratic campaign arm sounded a note of optimism.

“We are in a very strong position,” Rep. Suzan DelBene, D-Wash., told NBC News. “We have great candidates. We are with the American people on policy, in our message. We’ve had the resources to get out the vote and communicate with voters all across the country, and that has all put us in a very strong position today to take back the majority, take back the gavels and make Hakeem Jeffries our next speaker.”

Still, she warned that the battle for the majority could be close and take “a few days” to count all the votes.

“We may not know tonight,” DelBene said.

A full plate

The new Congress will have to work with the new president from the very start.

The Fiscal Responsibility Act, the product of a deal between President Joe Biden and then-Speaker Kevin McCarthy, extended the nation's debt limit until January 2025. The Treasury Department will be able to avert an immediate catastrophic debt default by using extraordinary measures to free up cash, but another bipartisan agreement will likely be needed.

The Senate will spend the first part of the New Year confirming the president’s judicial and Cabinet nominees, as well as hundreds of others nominated for other political roles.

If Republicans manage to win complete control of the White House and Congress, they will be in the same situation they were in 2016 — with Trump back at the helm.

In that scenario, Republicans will have to determine how to use budget reconciliation, an arcane process that would allow them to fast-track legislation without Democratic support: Do they push forward first with another round of Trump tax cuts? Or do they try once again to repeal or overhaul Obamacare, as they failed to do in 2017?

Johnson, whose political fate is tied to the outcome of the election, has recently said Republicans would go big and pursue a “massive reform” of the Affordable Care Act if his party wins.

“The ACA is so deeply ingrained, we need massive reform to make this work, and we got a lot of ideas on how to do that,” Johnson said at a campaign stop in Pennsylvania.

If Democrats are able to capture the White House and Congress, it would be a remarkable coup for a party faced with one of the most daunting Senate maps in the modern era. That would give Harris' aggressive economic agenda a fighting chance and put legislation to codify abortion rights high on the agenda.

This article was originally published on NBCNews.com