Voters in California head to the polls on June 5. And with Democrats leaning heavily on the state to deliver some of the 23 flipped seats needed to wrest back control of the House, the jungle-primary rule may once again trip them up.

For months, Democrats have entertained the possibility of it happening. But with election day approaching, the Democratic Congressional Campaign Committee (DCCC) is now taking aggressive steps to prevent what some strategists view as a calamity.

Officials at the committee said they have been investing hundreds of thousands of dollars in voter registration efforts, ads, and get-out-the-vote programs, which specifically target three districts represented by retiring Rep. Ed Royce (R-CA), incumbent Rep. Dana Rohrabacher (R-CA) and retiring Rep. Darrell Issa (R-CA). In addition, California Democrats have struck an agreement between two Democratic campaigns to cease negative ads against each other in the particularly nasty primary in California’s 39th District. And on Thursday, House Minority Leader Nancy Pelosi (D-CA) announced that members would be picking sides in some of the primary battles.