A year out from Election Day, eight of the top 10 most vulnerable House incumbents are Republicans. These are the members least likely to return to Congress in 2019.

Twenty-three Republicans sit in districts Hillary Clinton won last fall, but only four of them make the top 10. Two Democrats, both in districts President Donald Trump won, take two spots near the bottom. GOP strategists admit that if they can’t pass a tax overhaul, more Republicans will be in trouble because the party risks lower turnout from a disappointed base.

Democrats have historical trends on their side, and they’ve got energy — with a surge of candidates raising real money. But theirs is a tall order: They must gain 24 seats to win the majority. And the competitiveness of many of their targeted races will depend on which candidates emerge from potentially divisive primaries.

[Every 2018 Election, From Start to Finish]

This is just a snapshot of the overall House landscape. Open seats, which include pickup opportunities for both parties, are not part of this ranking.

Clinton carried Issa’s California district by 8 points in 2016. But unlike other Republicans in Clinton districts, Issa barely won a ninth term, winning by half a point against Democrat Doug Applegate. He voted for the GOP health care bill this year, which Democrats will likely highlight throughout the campaign. Applegate, a Marine veteran, is running again. Environmental lawyer Mike Levin and Navy veteran Paul Kerr are also running on the Democratic side. All of these challengers are raising significant money, but still trail Issa (who is extremely wealthy himself) in cash on hand.

[Every 2018 Election, From Start to Finish]

Lewis surprised many last year with his narrow victory over Democrat Angie Craig. Craig is back for a rematch with a new consulting team, hoping to connect better with the Minnesota district’s rural and working-class voters. A third-party candidate who cut into Craig’s base last fall doesn’t appear to be running again. A few other third-party candidates could still complicate the race for Craig. Lewis led Craig just 43 percent to 42 percent in PPP’s early October poll for Patriot Majority, a Democratic group. The same poll showed just 29 percent of respondents approve of Speaker Paul D. Ryan’s job performance, which Democrats will seize on to attack Lewis and his vote to repeal the 2010 health care law. On the surface, Faso might not look vulnerable with Trump carrying the New York district by 7 points and Faso winning his first term by 8 points last fall. But the central New York district voted twice for Obama, so Democrats see an opportunity here. The past two cycles, Democrats have run candidates who moved into the district to run for Congress. But this cycle, Democrats are poised to field a candidate with local roots to challenge Faso, who voted for the GOP health care plan. Iraq War veteran Pat Ryan and lawyer Antonio Delgado have emerged as the top candidates in the crowded field, both outraising Faso in the third fundraising quarter. Delgado even has more cash on hand than the incumbent.Democrats miscalculated last year, trying to tie Blum to Trump in an area where the president’s populist message resonated. Since then, the Freedom Caucus member voted for repeal of the 2010 health care law, which could hurt him in an Iowa district that twice voted for President Barack Obama by double digits. Democratic state Rep. Abby Finkenauer, a young candidate with strong ties to labor, looks to be a better fit for the district than the party’s 2016 nominee. Blum still has a cash on hand advantage, but Finkenauer’s third quarter haul wasn’t much less than his. She led the the two-term Republican 42 percent to 40 percent in an early-October PPP survey. The combination of Clinton carrying the California district and headlines linking Rohrabacher to Russia puts his re-election in question. Rohrabacher won a 15th term by 17 points in 2016. But since then, he has been at the center of some news stories raising questions about his pro-Russia views, with one Politico headline dubbing him “Putin’s favorite congressman.” House Majority Leader Kevin McCarthy even reportedly joked Rohrabacher was paid by the Russian president. Two of the Democrats vying to take on Rohrabacher, Harley Rouda and Hans Keirstead, have also been raising significant money. Keirstead, a stem cell researcher, is considered a top recruit.

Comstock has proved hard to beat in this affluent, suburban Virginia district that strongly rejected Trump. The former GOP operative has broken with her party on transportation issues that affect federal workers and voted against the Republican health care bill. But Democrats are salivating over her vote for the GOP’s budget blueprint last month, which called for eliminating a deduction for state and local taxes that benefits her constituents. At least three Democrats are raising serious money, and as long as they don’t destroy each other in a primary, one of them could be in a strong position to tie Comstock to Trump and Ryan. The speaker has an even higher disapproval rating than the president in the district, according to an October survey by PPP. Trump handily carried Tenney’s upstate New York district by 16 points, while Tenney won by a smaller 6-point margin in a race that featured a well-funded third party candidate. But the first-term congresswoman could have a formidable challenger who Democrats believe can win in the GOP-leaning district. State Assemblyman Anthony Brindisi, whose state Assembly district overlaps in part with the 22nd, has so far had the primary to himself. Brindisi has also outraised Tenney, bringing in twice as much as her in the third quarter.

O’Halleran defeated a flawed GOP candidate last cycle and is now facing his first re-election. A former Republican state legislator, O’Halleran joined the Blue Dog Caucus in Congress and, so far, has voted with his party less than the average House Democrat, according to CQ’s Vote Watch. Republicans have several candidates running here, and their nominee won’t be decided until late summer next year. But in a district that’s marginally voted Republican at the top of the ticket in recent cycles, O’Halleran is vulnerable as a freshman Democrat.

Nolan’s never had an easy race in his Minnesota district since returning to Congress in 2013. Despite lackluster fundraising, his retail political skills (and outside spending) have helped him hold on. Last fall, he won by just half a point while Trump carried the district by 16 points. This year, Nolan’s efforts to move closer to mining interests in the Iron Range have earned him a long-shot challenger for the Democratic-Farmer-Labor endorsement. After twice defeating wealthy businessman Stewart Mills, who said last week he’s not running, Nolan may face Pete Stauber, a Republican with more authentic ties to the district’s working-class voters. Stauber narrowly outraised Nolan.

Hurd is in a Toss-up race in a swing district that is also the largest in Texas. Clinton carried it by 3 points, and a Democrat won the seat as recently as 2012. Hurd has been touted as a rising star in the GOP, and he was re-elected in 2016 by 1 point. But the broader national environment and the diversity in the district (more than 70 percent of the population is Latino) puts it in play. Though a number of Democrats are vying to take on Hurd, some Democrats believe they could have a better chance with a new name. The previous holder, Democrat Pete Gallego, lost to Hurd in 2014 and a rematch last year.

Graphics by Sara Wise/Roll Call

Data sources: The Associated Press, Daily Kos Elections, states’ secretaries of state