Republicans' narrow majority in the House of Representatives enters Tuesday on the knife's edge, with both parties possessing paths to control in the next Congress.
More than a dozen Republicans hold seats in districts that President Joe Biden won in 2020, though many are putting up strong fights to keep their seats. A handful of Democratic incumbents are also running in districts that went for former President Donald Trump four years ago, but they, too, are working assiduously to run ahead of their national party.
Partisan redistricting has reduced the number of competitive seats across the country, but a few dozen remain up for grabs and hold the key to the speaker's gavel.
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Here are five House races to watch Tuesday that will help determine chamber control.
The open seat left by Rep. Abigail Spanberger, a Democrat who is running for Virginia governor in 2025, is a good barometer for Democrats' support among suburban voters that aren't big Trump fans.
The district, which stretches from the central Virginia exurbs of Washington to the Blue Ridge Mountains, voted against Trump by 2 points in 2016 and 7 points in 2020.
Democrat Eugene Vindman is facing off against Republican Derrick Anderson. Vindman has name recognition and strong fundraising from his and his brother's fame as whistleblowers under Trump, while Anderson, a combat veteran, is getting immense outside help from groups in Washington.
MORE: Trump campaign looks to Vance to help them over the finish line in PennsylvaniaEach side is looking to associate their opponents with the most extreme flanks of their respective parties, and both candidates, as first-time contenders, lack longstanding political ties to power players in the district.
Suburban seats like this are at the heart of the battlefield for the House, and Democrats' ability to keep seats like this in their column are key to flipping the chamber.
GOP Rep. Mike Lawler won his first term in 2022, marking an upset against then-Rep. Sean Patrick Maloney, the chair of House Democrats' campaign arm. Now, he'll have to face off against former Democratic Rep. Mondaire Jones to secure a second term and make a statement.
Lawler has depicted himself as a pragmatist rather than a Trump-aligned Republican while casting Jones as a progressive, including quotes of him saying "Defund the police." Jones, meanwhile, is also running in a moderate lane, voicing support for Israel and saying that his past remarks are being taken out of context, all while saying Lawler is untrustworthy on issues like abortion, which is also on the ballot this year in the form of a constitutional referendum.
Biden won Lawler's district by 10 points four years ago, though Lawler is still running a competitive race.
Lawler and other Republicans won a handful of seats in 2022 in the upper New York City suburbs and Long Island on the back of concerns over crime under Democratic leadership in the state. Lawler's race will be a test both of the lingering potency of those arguments and how first-term Republicans in the area fare in their first reelection bids in a presidential year.
If Lawler wins, it shows that Republicans could still find success messaging on crime -- and should he win with Harris replicating Biden's success, an indication of Republicans' strength protecting incumbents in blue-leaning seats.
Nebraska partially designates its Electoral College votes by congressional district, and with the 2nd Congressional District, anchored in Omaha, as the only competitive one, it has drawn outsized attention in the presidential race.
Trump and Republicans in the state fought hard to change state rules to a winner-take-all system just based on the statewide tally. They failed, however, and now Trump is getting washed out in polling and fundraising in the district, essentially ceding it to Harris, who has flooded the zone there.
MORE: How Nebraska’s 'blue dot' could prove pivotal in the Electoral CollegeThat's left veteran GOP Rep. Don Bacon in a tough spot.
Bacon is facing off in a rematch against Tony Vargas, a Democratic member of Nebraska's unicameral legislature.
Bacon has been an outspoken moderate and worked diligently to keep Trump at arm's length in a district that Biden won in 2020. However, his ability to win reelection in a district that his party's presidential nominee has all but given up on is a test of the dwindling trend of ticket-splitting.
New Mexico's 2nd Congressional District features a 2022 rematch between first-term Democratic Rep. Gabe Vasquez and former GOP Rep. Yvette Herrell, who he defeated two years ago.
The race is focusing largely on red meat issues -- abortion for Vasquez and immigration for Herrell. The district spans 180 miles of the U.S.-Mexico border.
MORE: What you need to know about Election Day exit pollsVasquez has sought to seize on past remarks from Herrell in which she said she wishes "we could have eliminated all abortion in this state." Herrell has not disavowed any of her past stances, touting her support for legislation offering legal personhood to fertilized eggs, which would essentially ban abortion and treatments like in vitro fertilization.
Herrell's counter argument is that voters actually care more about illegal border crossings.
Vasquez comes into the race with a fundraising advantage, but the victor in this race could indicate whether key aspects of each party's message resonates with voters in swing districts.
Democratic Rep. Mary Peltola won her first term in 2022 in an experiment of Alaska's first statewide ranked-choice election. Now, she'll have to pull off the feat again in a presidential year.
There are two main obstacles Peltola will have to overcome. First, Republicans are more unified this time around Nick Begich, likely leaving less division among GOP voters even in a ranked-choice format. And second, she'll share a ballot with Harris and Trump.
Trump won Alaska by 10 points in 2020 and the state is far from competitive at the presidential level.
Peltola has sought to maintain her appeal by focusing on hyper local issues like fishing, boasting on her website that she has "reduced Chum bycatch by 87%."
Like Republicans in similar situations, Begich is working to convince voters that Peltola is not the moderate she says she is. Whether he succeeds could be a good gauge of how much a laser-focus on local issues can break through in a national climate.