Left-wing billionaire and environment activist Tom Steyer is reportedly pouring millions of dollars into Orange County, California, to mobilize millennial voters to turn at least four at-risk red seats blue and shift the Republican majority in the House of Representatives.

“This county [Orange County] is possibly the single most significant county in terms of controlling the House of Representatives,” Steyer told the Voice of OC on January 12.

Steyer has supported both Hillary Clinton and Barack Obama.

Through his nonprofit, NextGen, Steyer announced last week that he is launching a $30 million grassroots program across ten states that seeks to mobilize millennials to vote in the 2018 midterm election.

According to the Public Policy Institute of California, Millennials (age 18 to 35) make up 35 percent of California’s adult population. However, just 60 percent of the Golden State’s millennials are reportedly registered to vote.

The seats of incumbents Rep. Darrell Issa (R-Vista) and Chairman of the House Foreign Affairs Committee Rep. Ed Royce (R-Fullerton), who announced they are retiring last week, are at risk. Rep. Mimi Walters (R-Irvine) and Rep. Dana Rohrabacher (R-Costa Mesa) are also being targeted.

The Hill notes:

If Democrats are to reclaim the majority in the House of Representatives this year, they will almost certainly do so with the help of Minority Leader Nancy Pelosi’s home state, where multiple favorable waves are building. Almost a third of the House districts that elected a Republican but voted for Hillary Clinton for president in 2016 are in California. Almost all of those districts have seen explosive demographic growth that benefits Democrats

Progressives have already begun their campaigns to undermine Republican legislators. In November, Breitbart News reported that “a coalition of liberal and labor groups named “Not One Penny” began airing a series of television ads … targeting five of California’s Republican members of Congress over the GOP’s tax reform plan.”

In October, Steyer spent $10 million to air a nationwide TV ad calling for President Donald Trump’s impeachment.

The Democrats are not the only ones on the offensive. Last year, the National Republican Congressional Committee (NRCC) named four Democratic California congressmen it plans to target and defeat in this year’s midterm elections, namely Reps. Ami Bera (D-Elk Grove, 7th district), Salud Carbajal (D-Santa Barbara, 24th district), Scott Peters (D-San Diego, 52nd district) and Raul Ruiz (D-Palm Springs, 36th district).

Adelle Nazarian is a politics and national security reporter for Breitbart News. Follow her on Facebook and Twitter.