WASHINGTON — With a year to go before the midterm elections, the defining political issue of 2026 is still not certain. But what is clear so far is that mid-decade redistricting will have a major impact on the House battlefield.

Newly enacted maps in a handful of states have influenced where some lawmakers land on our top 10 list of the most vulnerable House incumbents 365 days before Election Day 2026.

Of course, incumbents from the most evenly split and competitive House districts continue to dominate the list. But the top two spots are claimed by a pair of Democrats, Don Davis of North Carolina and Vicente Gonzalez of Texas, whose districts were made significantly redder by state Republicans after President Donald Trump called for new maps to help the GOP defend its narrow House majority next year.

To compile this list, CQ Roll Call’s campaign team relied on interviews with party insiders, district dynamics, past results, candidates’ campaign finances, race ratings by Inside Elections with Nathan L. Gonzales and district-level presidential performance, as calculated by Inside Elections. We only looked at incumbents and not at open seats, which could also flip and affect party control.

This month’s list excludes vulnerable lawmakers from California, where the state’s House map had not been finalized as of publication time. Golden State voters are weighing in Tuesday on Proposition 50, a ballot measure that would rubber-stamp a Democrat-drawn map for the next three election cycles. That means we left off two freshman Democrats — Adam Gray, who topped the list in May, and Derek Tran, who came in at No. 5. — and did not consider five House Republicans who could be vulnerable if the referendum passes: Doug LaMalfa, Kevin Kiley, Ken Calvert, Darrell Issa and David Valadao.

We’ve also held off on including Missouri Democrat Emanuel Cleaver II, who would be at or near the top of the list after his Kansas City-area district was carved up by the GOP-led legislature. But Missouri Democrats have begun an initiative process to place the map on the ballot in 2026, which could block it from being used next year. An advocacy group, People Not Politicians Missouri, has until next month to gather enough signatures, but if the current map holds, Cleaver will almost certainly move onto the list should he choose to seek reelection.

The new map in Texas has left some Democrats still sorting out which districts they plan to run in. Rep. Julie Elizabeth Johnson, for instance, has seen her Dallas-area district transform into a heavily red seat that stretches into East Texas and it’s unclear where she will seek reelection next year.

With the recent adoption of a new map in Ohio, longtime Democratic Rep. Marcy Kaptur makes our list, after her Trump-voting district shifted further right.

And more redistricting targets could be joining her in future editions of this list. A state judge in Utah has until Nov. 10 to choose new congressional lines after ruling earlier this year that the state’s current GOP-drawn map did not comply with Utah’s redistricting standards.

Legislators in Indiana and potentially Kansas are expected to meet this year to consider new Republican-initiated map changes, while Democratic legislators in Virginia have begun a process aimed at amending the commonwealth’s constitution to allow for mid-decade redistricting. New boundaries in Florida remain on the table as well.

Redistricting notwithstanding, the typical dynamics of a midterm election are still in play. The House represents the best chance for Democrats to cut into full GOP control of Washington, but Republicans are looking to build on their 2024 success to maintain and grow their majority.

History dictates that midterm elections in a president’s second term favor the party out of power. Democrats are hammering Republicans over their massive tax and spending bill enacted over the summer, particularly its health care provisions, and over the economy more broadly. Republicans are confident that popular provisions in the new law, such as no tax on tips, will win support from voters. And it remains to be seen whether the ongoing partial government shutdown will resonate with voters a year from now.

Several lawmakers, including longtime Democratic incumbents, are facing primary challenges this cycle. Some of their primary opponents appear to be building legitimate campaigns, and those incumbents could join future versions of this list as the dynamics become clearer.

1. Don Davis (D)

North Carolina's 1st District

Race rating: Tilt Republican

Davis was first elected in 2022, but Republican state lawmakers have since twice redrawn the boundaries of his northeastern North Carolina district. Their most recent effort shifts the seat from one that Trump carried by 3 points to one that would have backed him by 12 points. Davis hasn’t said whether he’ll seek reelection to his current seat or challenge GOP Rep. Greg Murphy in the new 3rd District, which now includes Davis’ home in Snow Hill. Republican hopefuls in the 1st District include state Sen. Bobby Hanig and Rocky Mount Mayor Sandy Roberson. Davis entered October with $1.6 million in the bank. Roberson, who has loaned his campaign $3 million, had $2.4 million on hand, Hanig $246,000 and Murphy $2.1 million.

2. Vicente Gonzalez (D)

Texas' 34th District

Race rating: Toss-up

Gonzalez, a political moderate serving his fifth term, represents a Latino-majority border district that swung more than 15 points toward Trump in 2024. And that was before Texas Republicans passed a new gerrymander that made his South Texas district even more favorable to the GOP. Despite the new map, Gonzalez has said he intends to run for reelection. He outperformed Kamala Harris in 2024 and has criticized his party for moving too far to the left on abortion and transgender rights. Gonzalez ended September with $1.3 million stockpiled, besting two leading Republican challengers: former Rep. Mayra Flores, whom Gonzalez beat in both 2022 and 2024, and Army veteran and attorney Eric Flores (no relation to the former congresswoman).

3. Gabe Evans (R)

Colorado's 8th District

Race rating: Toss-up

Evans is seeking a second term in Colorado’s most competitive district, which reaches from the northern fringe of the Denver metro area to Fort Lupton and Greeley. Several Democrats are seeking to defeat him, including state Reps. Manny Rutinel and Shannon Bird, state Treasurer Dave Young and Marine veteran Evan Munsing. Former Rep. Yadira Caraveo, who held the seat for a single term before Evans ousted her in 2024, briefly launched, then dropped, a comeback bid. Evans had nearly $2 million in his campaign account at the start of October, far more than any of the Democrats in the race.

4. Ryan Mackenzie (R)

Pennsylvania's 7th District

Race rating: Toss-up

Mackenzie’s 1-point win last year in this Lehigh Valley swing district came with Trump boosting Republicans across Pennsylvania as he completed a nationwide sweep of battleground states. With Democratic Gov. Josh Shapiro at the top of the ticket next year, the down-ballot effects could be different, though Republicans see Mackenzie in a strong position. Democrats are locked in a crowded five-way primary between Northampton County Executive Lamont McClure, former federal prosecutor Ryan Crosswell, former utility company executive Carol Obando-Derstin, Lehigh County Controller Mark Pinsley and firefighter union head Bob Brooks. Mackenzie’s fundraising dipped in the third quarter, but, at $1.4 million, he still has a significant cash-on-hand advantage over his Democratic rivals.

5. Mariannette Miller-Meeks (R)

Iowa's 1st District

Race rating: Toss-up

It took Miller-Meeks four tries to win her House seat in Iowa’s southeastern corner; one of her Democratic opponents, former state Rep. Christina Bohannan, is hoping to do it in three. Miller-Meeks barely edged Bohannan in 2024, winning by 798 votes, but supporters of the third-term Republican say the close call prompted her to bolster her fundraising efforts. She’s brought in more than $3 million so far this cycle and ended September with $2.6 million on hand. Bohannan, a law professor, has raised nearly $2 million since launching her bid and had $1.6 million banked. Both will need to get past primary challengers before squaring off for the third time. Miller-Meeks once again faces Gold Star dad David Pautsch, who took 44% of the primary vote last year. Bohannan’s primary opponents include attorney Taylor Wettach and health care worker Travis Terrell.

6. Jared Golden (D)

Maine's 2nd District

Race rating: Tilt Democratic

Golden remains a top Republican target next year in his rural district, which delivered for Trump an Electoral College vote for the third straight election last year. But for the first time since his initial 2018 race, Golden faces a primary challenger, with state Auditor Matt Dunlap launching a challenge last month. Golden has continued to buck his party occasionally — most recently, he was the only House Democrat to vote to avert the ongoing government shutdown, though he opposed Republicans’ tax and spending measure earlier this year. National Democrats argue that Golden is their best chance to hold the seat. Waiting on the other side of the primary will likely be Republican former two-time Gov. Paul LePage, who carried the 2nd District in his unsuccessful 2022 comeback bid. Golden entered October with a cash edge over his GOP rival — $1.7 million to $716,000 — but polling has shown he’s in for a tough race next year.

7. Marcy Kaptur (D)

Ohio's 9th District

Race rating: Tilt Republican

The longest-serving woman in congressional history, the 79-year-old Kaptur is a political survivor who has managed to keep winning despite Ohio’s shift from a purple battleground to a comfortably red state. But the latest redraw of her Toledo-anchored district might spell the end of a House career now in its fifth decade. Under the state’s new map, the 9th District shifts from one Trump carried by 7 points to one he would have carried by 11 points. Republicans lining up to take on the congresswoman include 2024 nominee Derek Merrin, a former state representative who lost to Kaptur by fewer than 2,400 votes, state Rep. Josh Williams and Air Force veteran Alea Nadeem. Ohio Senate President Rob McColley, whose home now falls within the new district, could run as well. Kaptur dominated her Republican opponents in fundraising, the latest filings showed, with $1.2 million in her coffers on Sept. 30.

8. Mike Lawler (R)

New York's 17th District

Race rating: Toss-up

With Don Bacon announcing his retirement in June, Lawler is now the only Republican holding a seat carried by Kamala Harris on this list. (Pennsylvania’s Brian Fitzpatrick has a more proven electoral record in his Harris-supporting district in suburban Philadelphia.) Lawler is once again a top target for Democrats, who have a crowded primary to pick their nominee in this lower Hudson Valley district. Rockland County Legislator Beth Davidson and Army veteran Cait Conley are seen as top Democratic contenders and entered October with $657,000 and $950,000 on hand, respectively. But those totals were dwarfed by Lawler’s $2.8 million. Still, next year is the congressman’s first midterm election as an incumbent as he tries to parlay his image as a relative moderate into a third term.

9. Juan Ciscomani (R)

Arizona's 6th District

Race rating: Toss-up

Ciscomani prevailed twice over Democratic former state Sen. Kirsten Engel, but in his quest for a third term, he faces a new opponent: Marine veteran JoAnna Mendoza, who grew up in a working-class family in southern Arizona. Ciscomani, who was born in Mexico and is the first Latino Republican to represent Arizona in the House, has focused on water security, a key concern in the district tucked into the state’s southeastern corner. Mendoza has emphasized economic issues and Republican-enacted cuts to Medicaid. Mendoza narrowly topped Ciscomani in third-quarter fundraising, $696,000 to $613,000, although the congressman ended September with $2.4 million in his campaign coffers, far ahead of his opponent’s $950,000.

10. Marie Gluesenkamp Pérez (D)

Washington's 3rd District

Race rating: Tilt Democratic

Gluesenkamp Pérez twice beat Republican Joe Kent, a retired Green Beret and MAGA favorite, in this southwest Washington district that’s a mix of rural, suburban and urban communities. This time, she’s facing John Braun, the top Republican in the Washington Senate, with Kent taking a top counterterrorism role in the Trump administration. Republicans are hoping Braun’s government experience and less combative approach to politics will appeal to the district’s independent-minded voters who were turned off by Kent. But Democrats say Gluesenkamp Pérez’s voting record and willingness to occasionally buck her party will once again help her prevail. The congresswoman had $1.9 million in the bank at the end of the third quarter, while Braun, who entered the race in August, had less than one-third of that.

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