Control of the House and Senate is up for debate in the 2024 elections as voters elect a new Congress

WASHINGTON – Americans are about to elect a new Congress, with control of both chambers at stake as every House seat and a third of the Senate go before voters on Election Day.

Every non-incumbent president since 1992 has taken office with their party controlling both chambers of Congress, but there is no guarantee that will be the case for either Kamala Harris or Donald Trump this year.

The stakes are high as the Senate is tasked 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 bills that need to be passed.

The Republicans wanted to win the Senate

Democrats currently have a 51-49 lead in the Senate, but Republicans are expected to win the majority. They are all but guaranteed to win an open seat in ruby-red West Virginia as Democratic independent Sen. Joe Manchin retires.

That seat alone would be enough for the GOP to control the chamber if Trump wins the presidency. In that 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 trying to flip Democratic-held seats in the red states of Montana and Ohio, where Democratic Senators Jon Tester and Sherrod Brown will once again have to defy gravity in states where Trump is expected to win by a wide margin. 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 hotly contested at the presidential level: Sen. Bob Casey in Pennsylvania; an open seat in Michigan, where Sen. Debbie Stabenow is retiring; Senator Tammy Baldwin of Wisconsin; an open seat in Arizona, where Democrat-turned-independent Sen. Krysten Sinema is retiring; and Senator Jacky Rosen in Nevada.

Meanwhile, Democrats' best hopes are for Republican-held seats 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, populist independent candidate Dan Osborn is competing against low-profile Republican Sen. Deb Fischer in a race that could pull off an upset.

A close fight for the House of Representatives

The race for the House of Representatives is on a knife's edge.

The Republicans currently have a majority of 220 to 212, with three seats open – two in safe blue seats, one in a safe red seat. The Democrats only need to gain four seats to take control of the House of Representatives and with it the speaker's gavel and the To become chairman of all committees.

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

In particular, the blue states of New York and California are home to ten extremely competitive House districts. Harris is expected to handily win both of those states at the presidential level, but Republicans are investing heavily in retaining and exploiting electoral seats there.

In New York, the Republicans are defending four seats that they swapped in 2022, thereby securing the majority in the House of Representatives. Those seats are filled by Reps. Marc Molinaro, Mike Lawler, Anthony D'Esposito and Brandon Williams, all of whom are seeking re-election. D'Esposito and Williams counties are classified as “lean Democratic” by the Cook Political Report because the party has used Laura Gillen and John Mannion to try to recapture those seats. Lawler's race is classified as “lean Republican.” Meanwhile, in the Hudson Valley, Rep. Pat Ryan, D-N.Y., faces a tough challenge from Republican Alison Esposito in a race classified as “lean Democrat.”

And in Central and Southern California, at least five Republican incumbents also face tough reelection bids.

Freshman Rep. John Duarte faces Democrat Adam Gray in the 13th District; Rep. David Valadao has a rematch against Democrat Rudy Salas in the 22nd District; Rep. Mike Garcia fends off a challenge from Democrat George Whitesides in the 27th District; Longtime Rep. Ken Calvert is trying to stop Democrat Will Rollins in the 41st District; and Rep. Michelle Steel is running against Democrat Derek Tran in the 48th District.

Speaker Mike Johnson, R-La., and the man seeking to replace him, Minority Leader Hakeem Jeffries, D-N.Y., have spent the last few weeks targeting these key House battlegrounds as well as a number of swing districts in Pennsylvania traverse. Michigan, Arizona, Nevada and the Pacific Northwest.

As the polls opened Tuesday morning, the chairman of the Democratic campaign group in the House of Representatives expressed optimism.

“We are in a very strong position,” Rep. Suzan DelBene, D-Wash., told NBC News. “We have great candidates. With our message, we are politically on the side of the American people. We had the resources to reach and communicate with voters across the country, and that put us all 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 fight for the majority could be close and it could take “a few days” for all the votes to be counted.

“We may not know tonight,” DelBene said.

A full plate

The new Congress must work with the new president from the start.

The Fiscal Responsibility Act, the result of an agreement between President Joe Biden and then-Speaker Kevin McCarthy, extended the country's debt limit until January 2025. The Treasury will be able to avert an immediate catastrophic debt default by taking extraordinary cash relief measures, but another bipartisan agreement will likely be required.

The Senate will spend the first part of the new year confirming the president's judicial and Cabinet nominees, as well as hundreds of other nominees for other political offices.

If Republicans manage to gain complete control of the White House and Congress, they will find themselves in the same situation as in 2016 – with Trump back at the helm.

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

Johnson, whose political fate depends on the outcome of the election, recently said Republicans would make a major effort and seek “massive reform” of the Affordable Care Act if his party wins.

“The ACA is so entrenched that we need comprehensive reform to make it work, and we have a lot of ideas about how to do that,” Johnson said at a campaign stop in Pennsylvania.

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