California Republicans are on the verge of becoming an endangered species on Capitol Hill.

On Wednesday, Rep. Darrell Issa (R-CA), a top House Republican and the former chairman of a powerful committee, became the 31st GOP congressman to announce he would not seek re-election this year. He is also the second California Republican this week to call it quits in a midterm cycle that has Republicans increasingly worried about maintaining their majorities on Capitol Hill.

As part of their quest to take back control of the House in the midterm elections, Democrats are targeting vulnerable House Republicans whose constituents chose Hillary Clinton over Donald Trump in the 2016 election. Seven of those seats are in the Golden State. In order to regain a majority in the House, Democrats must flip at least 24 GOP-held seats.

Issa was particularly vulnerable, having narrowly won re-election by just half a percent in 2016 while Clinton defeated Trump in his district by eight points. Issa’s Republican colleagues on Capitol Hill candidly acknowledged that his retirement—and that of other members from toss-up districts—has the potential to fuel a Democratic wave in 2018.

“Obviously any time that you see long-serving Republican members in swing districts retiring, it’s not welcome news for the Republicans. It certainly would be encouraging news if I were on the Democratic side of the aisle,” Rep. Mark Meadows (R-NC), the chairman of the powerful House Freedom Caucus, told The Daily Beast. “Certainly if I were looking at the retirement of some of these members in swing states and swing districts, it would indicate that there’s a great chance for a Democrat pickup of that seat. Just being honest.”

Ten months before Election Day, Republicans are fearing a wave. Earlier this week, 13-term Rep. Ed Royce (R-CA), the chairman of the House Foreign Affairs Committee, also announced he was retiring from Congress—the seventh Republican committee chair to call it quits after 2018. While Royce won re-election in 2016 by 15 points, Clinton won his district by nine points, giving Democrats a major opening to flip the seat.

California’s 49th District, which Issa has represented for 18 years, has been a prime target for the Democratic Congressional Campaign Committee, the party’s House campaign arm.

Additionally, in early 2017, the National Republican Congressional Committee flagged Issa’s district as one where the incumbent was in danger.

But the NRCC was bullish on Wednesday in the face of Issa’s sudden retirement, putting a positive spin on what many Republicans are openly acknowledging is an increasingly difficult task. Rep. Steve Stivers (R-OH), the NRCC chairman, predicted that the Democratic candidate would suffer a brutal primary race in a crowded field of candidates, giving Republicans the upper hand in a difficult race.

“In the 49th District, Democrats are locked in what is fast becoming one of the bloodiest primaries in America,” Stivers said. “While Democrats fight with each other, Republicans will focus on fighting Democrats—and that’s how we plan to win. We look forward to facing whoever limps out of the Democrats’ battle royale: black and blue, and broke.”

The district’s primary election on June 5, will send the top two vote-getters—regardless of party affiliation—to face off in the general election. It is conceivable, but unlikely, that both candidates will be from the same party.

After Issa announced his retirement, the NRCC sent out a series of talking points for its surrogates. The list, obtained by The Daily Beast, underscores that Republicans will be keeping tabs on the Democratic primary, hoping for a contest that results in a candidate who is damaged beyond repair, and it shows that Republicans will continue to tie House Minority Speaker Nancy Pelosi’s (D-CA) unpopularity to any Democratic candidate.

“We have been preparing to run tough races in each of these districts, and we are ready to face whatever out-of-touch liberal emerges through the bloody Democratic primary,” according to one of the talking points.

Democrats in the state, however, are just as confident about their chances to flip Issa’s seat. Operatives argue that President Donald Trump’s brand is toxic in the liberal state and that the recent tax bill he signed, supported by many Republican members from California—Issa excluded—disproportionately impacts voters there.

“With the recent announced retirements of Darrell Issa and Ed Royce, it shows the competitiveness of those districts and the pick-up opportunities that truly exist,” Rep. Ben Ray Lujan, the chairman of the DCCC, told The Daily Beast in an interview, adding that he’s “encouraged” by the national and grassroots interest in the California races.

Issa won by a little more than 1,600 votes against Democrat Doug Applegate, who is running for the seat again this year.

But Applegate first has to face off with, among others, Mike Levin, an environmental attorney and former executive director of the Democratic Party of Orange County.

“I’m sure that every member is going to be looking at folks like Issa and Royce and making their own determination,” Levin told The Daily Beast on Wednesday. “I think that in our district specifically, the tide has definitely turned. Darrell Issa saw the writing on the wall.”

Levin, who has been endorsed by Rep. Adam Schiff (D-CA), said he was surprised to hear the announcement and his phone had been ringing off the hook all morning. He was adamant, too, about not using Applegate as a punching bag, acknowledging that the district is crucial to the party’s overall efforts this year.

“It’s important in all these districts that we try to remain united after the primaries,” Levin said.

Two other California districts, represented by Republican Reps. Steve Knight and David Valadao, are also on Democrats’ target list. Knight and Valadao have not revealed their plans yet. And amid the high-profile retirements, Rep. Dana Rohrabacher (R-CA)—whose seat is also in play—pledged to stay put.