President Trump called Democratic mega-donor Tom Steyer "wacky and totally unhinged" over his ad campaign calling for Trump's impeachment.

"Wacky & totally unhinged Tom Steyer, who has been fighting me and my Make America Great Again agenda from beginning, never wins elections!" the president tweeted.

Wacky & totally unhinged Tom Steyer, who has been fighting me and my Make America Great Again agenda from beginning, never wins elections! — Donald J. Trump (@realDonaldTrump) October 27, 2017

Steyer has blanketed cable news airwaves with $10 million in advertisements laying out the case for Trump's impeachment. In the ad, Steyer criticizes Trump's actions on health care, immigration and the environment and says a Republican Congress impeached Bill Clinton William (Bill) Jefferson ClintonInviting Kim Jong Un to Washington Howard Schultz must run as a Democrat for chance in 2020 Trump says he never told McCabe his wife was 'a loser' MORE for less serious conduct.

Tomorrow morning might be interesting: I'm told Tom Steyer's ad on impeaching Trump is going to play on Fox + Friends for the first time... — Gabriel Debenedetti (@gdebenedetti) October 25, 2017

Steyer also launched a digital ad buy on Thursday night, pressing House Minority Whip Steny Hoyer (D-Md.) to support impeaching Trump. The Facebook ads for the campaign, which were first shared with The Hill, encourage Hoyer’s constituents to sign Steyer’s petition, which calls on Congress to support impeaching the president.

The Democratic donor is active in environmental causes and has been seen as a possible primary challenger for Sen. Dianne Feinstein Dianne Emiel FeinsteinHillicon Valley: Senators urge Trump to bar Huawei products from electric grid | Ex-security officials condemn Trump emergency declaration | New malicious cyber tool found | Facebook faces questions on treatment of moderators Ocasio-Cortez adviser says Sunrise confrontation with 'old-timer' Feinstein 'sad' Key senators say administration should ban Huawei tech in US electric grid MORE (D-Calif.).