House Democrats’ campaign committee has officially chosen sides in the battle to face Rep. Dana Rohrabacher (R-CA) in the fall, throwing their weight behind businessman Harley Rouda (D) over businessman Hans Keirstead (D).

“Harley has demonstrated that he is the strongest Democrat in this race and best prepared for the general election, and with the grassroots and numerous California delegation members strongly behind him, we know we will flip this district this fall,” DCCC Chairman Ben Ray Luján (D-NM) said in a statement.

The move is an attempt to avoid the disaster of the two Democrats evenly splitting the vote and giving Republicans a chance of pushing through two candidates in the fall.

California’s unusual top-two all-party “jungle primary” means that the two candidates of any party who finish at the top in the June 5 primary advance to the general election, and this is one of five swing seats where Democrats have been worried they might blow their chances at winning by being locked out completely.

Rohrabacher’s deep flaws as a candidate make him vulnerable in the fall — but have also opened the door to a serious GOP challenge from Scott Baugh, a popular local lawmaker.

Democrats have been warily watching this race since it might be their biggest risk of getting shut out in June. But national Democratic interference has the risk of backfiring by infuriating local activists. To that end, the DCCC’s endorsement was paired with strong backing by local Democratic activists, with a joint statement with the district’s local Indivisible group.

“We’ve been hard at work for more than a year to defeat Dana Rohrabacher and bring change to our district,” the leaders of Indivisible Orange County 48 said in a joint statement. “We believe that the only way we can accomplish this goal is by Democrats and like-minded Independents and Republicans to unite around Harley Rouda, a strong progressive whom we were proud to endorse last week. We appreciate the DCCC following our lead and standing with Harley Rouda and grassroots organizations like Indivisible.”

Even so, the move is likely to ruffle some feathers. Keirstead has some significant local support as well, including an endorsement from the California Democratic Party, an organization that’s largely been taken over by hardline progressive activists.