Democrats are so concerned about getting shutout of their chance to flip three GOP-held districts in Southern California in the state’s jungle primary system that they are pouring $1.5 million into three districts this week targeting top Republican candidates.

One Democratic-Party-funded television ad stands out because it bashes a leading Republican candidate for twice voting with Democrats and California Gov. Jerry Brown in the state legislature.

All candidates regardless of party affiliation in California compete in the primary, and the top two vote getters then run in the general election.

Democratic leaders have repeatedly stated that their House majority takeover runs through California, where there are seven districts held by Republicans that voted for Hillary Clinton over Donald Trump in 2016.

However, Democratic Party insiders for months have openly worried about a nightmare scenario: that they could get locked out of the general in three California districts, those held by retiring GOP Reps. Darrell Issa and Ed Royce, as well as Rep. Dana Rohrabacher.

In final weeks before the June 5 primary, Democrats have become so concerned they are attacking one GOP state representative running for Issa's seat for twice voting with Democrats in the state legislature.

The Democratic Congressional Campaign Committee (DCCC) this week spent a reported $515,000 in Issa's district, and announced a television ad targeting GOP State Assemblyman Rocky Chavez.

The ad slams Chavez for voting with Democrats for California Gov. Jerry Brown's budget, which it referred to as the "largest budget in California state history," and for voting to raise "your gas and energy costs," both strong Republican talking points.

"Californians deserve leaders who keep their word, not more career politicians who promise voters one thing and do another in Sacramento," DCCC spokesman Drew Godinich said in a statement.

The DCCC did not respond to a Free Beacon question asking it why it funded an ad hitting Chavez for voting for Brown’s 2017 budget and the cap and trade bill, dubbed the California Global Warming Solutions Act of 2006, when combating climate change is a major pillar of the Democratic platform.

The ad does not mention that a recent poll has Chavez leading all the other candidates, garnering the support of 16 percent of likely voters. That puts him ahead of the top Democratic candidate, Doug Applegate, the previous frontrunner, who came within 1,600 votes of defeating Issa in 2016.

Applegate raked in 12 percent of voters, putting him in second place.

National Democrats have split the Democratic vote by pushing lawyer Mike Levin as their candidate of choice, and he and Applegate are now vying for the No. 2 spot.

However, another GOP candidate, Board of Equalization member and former state legislator Diane Harkey, is right on their heels. Republican insiders believe she has surged and is now leading the pack of candidates, boosted by population-dense GOP stronghold of Orange County, which she represented in the state legislature.

She also has the vocal support of popular conservative radio host Carl DeMaio.

DeMaio regularly touts Harkey's candidacy on his program, as well as her strong, early support for Orange County's revolt against California's sanctuary state law.

Politico's California Playbook Tuesday also reported that the DCCC is spending $722,000 this week to try to prevent a lockout in Royce's district. The House Democrats' campaign arm additionally placed a $98,000 radio ad buy in the Los Angeles market with the "precise target unknown."

At the same time, the liberal Priorities USA Action and the House Majority PAC Tuesday announced a combined $270,000 digital ad campaign targeting GOP candidates in the Issa, Royce, and Rohrabacher districts.

The ad campaign, which runs through June 5, targets the candidacies of Republicans Scott Baugh in the 48th district, Shawn Nelson in the 39th, and Chavez in the 49th.

"As Democrats work to retake the House this November, we need to make sure that we're maximizing our opportunities to win, which, in California, means ensuring at least one Democrat makes it onto the general election ballot," Patrick McHugh, executive director of Priorities USA Action, said in a statement. "Southern California voters deserve to have all the facts before they cast their ballots, especially with such a crowded field of candidates."