The narrow majority of Republicans in the House of Representatives enter Tuesday on the edge of a knife, with both parties having paths to take control of the next Congress.

More than a dozen Republicans hold seats in districts won by President Joe Biden in 2020, although many are fighting vigorously to keep their seats. A handful of Democratic incumbents are also running in districts that were elected four years ago by former President Donald Trump, but they, too, are working diligently to get 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 president’s gavel.

How to watch ABC News is covering the 2024 election results live.

Here are five House races to watch on Tuesday that will help determine control of the chamber.

7th District of Virginia

The vacant seat left by Rep. Abigail Spanberger, a Democrat running for Virginia governor in 2025, is a good barometer of Democratic support among suburban voters who are not big Trump fans.

The district, which stretches from Virginia’s central Washington suburbs to the Blue Ridge Mountains, voted against Trump by 2 points in 2016 and 7 points in 2020.

Democrat Eugene Vindman faces Republican Derrick Anderson. Vindman enjoys notoriety and strong fundraising thanks to his and his brother’s fame as whistleblowers under Trump, while Anderson, a combat veteran, receives immense outside help from the share of groups in Washington.

Each camp seeks to associate its opponents with the more extremist flanks of their respective parties, and both candidates, as first-time candidates, do not have long-standing political ties to power players in the district.

Suburban seats like this are the heart of the battleground for the House, and Democrats’ ability to keep seats like this in their column is critical to flipping the House.

17th district of New York

GOP Rep. Mike Lawler won his first term in 2022, scoring an upset over then-Rep. Sean Patrick Maloney, chairman of the House Democrats’ campaign arm. He will now face former Democratic Rep. Mondaire Jones to secure a second term and make a statement.

Lawler described himself as a pragmatist rather than a Trump-aligned Republican while portraying Jones as a progressive, including quotes of him saying “Defund the police.” Jones, meanwhile, is also running a moderate route, expressing support for Israel and saying his past remarks are taken out of context, while asserting that Lawler is untrustworthy on issues like abortion, which is also on the ballot this year. form of a constitutional referendum.

Biden won Lawler’s district by 10 points four years ago, although Lawler still runs a competitive race.

Lawler and other Republicans won a handful of seats in 2022 in the Upper House. new York The city’s suburbs and Long Island due to concerns about crime under the state’s Democratic leadership. Lawler’s race will be a test of both the enduring power of those arguments and how the region’s first-term Republicans will fare in their first attempts at re-election in a presidential year.

If Lawler wins, it shows Republicans could still find messages of success on crime — and if he wins with Harris replicating Biden’s success, an indication of Republicans’ strength in protecting incumbents in blue-leaning seats .

Nebraska’s 2nd District

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 attracted outsized attention in the presidential race.

Trump and state Republicans fought hard to change the state’s rules to a winner-takes-all system based solely on statewide counting. They failedHowever, and now Trump is being swept in the polls and fundraising in the district, essentially ceding it to Harris, who has flooded the area there.

That left veteran GOP Rep. Don Bacon in a tough spot.

Bacon faces Tony Vargas, a Democratic member of Nebraska’s unicameral legislature, in a rematch.

Bacon has been an outspoken moderate and has worked diligently to keep Trump at bay in a district that Biden won in 2020. However, his ability to win re-election in a district that his party’s presidential nominee has all but abandoned is a test of the downward trend in ticket sharing.

New Mexico’s 2nd District

New Mexico’s 2nd Congressional District features a 2022 rematch between first-term Democratic Rep. Gabe Vasquez and former Republican Rep. Yvette Herrell, whom he defeated two years ago.

The race focuses largely on red meat issues: abortion for Vasquez and immigration for Herrell. The district stretches 180 miles from the U.S.-Mexico border.

Vasquez sought to build on Herrell’s past remarks in which she said she wished “we could eliminate all abortion in this state.” Herrell has not disavowed any of his past positions, touting his support for legislation granting legal personality to fertilized eggs, which would essentially ban abortion and treatments like in vitro fertilization.

Herrell’s counterargument is that voters care more about illegal border crossings.

Vasquez comes into the race with a fundraising advantage, but the winner of this race could indicate whether key aspects of each party’s message resonate with voters in swing districts.

General District of Alaska

Democratic Rep. Mary Peltola won her first term in 2022 in an experiment in Alaska’s first statewide ranked-choice election. Now she will have to achieve this feat again during a presidential year.

Peltola will have to overcome two main obstacles. First, Republicans are more united around Nick Begich this time, likely leaving fewer divisions among GOP voters, even in a ranked-choice format. And second, she will share a ballot with Harris and Trump.

Trump won Alaska by 10 points in 2020 and the state is far from presidentially competitive.

Peltola has sought to maintain its appeal by focusing on hyper-local issues like fishing, boasting on its website that it has “reduced Chum’s bycatch by 87 percent.”

Like Republicans in similar situations, Begich is working to convince voters that Peltola is not the moderate she claims to be. Its success could be a good indicator of the extent to which a focus on local issues can penetrate a national climate.