California billionaire Tom Steyer’s $10 billion campaign pushing for Donald Trump’s impeachment has apparently gotten under the president’s skin.

Trump lashed out at Steyer Friday morning, calling him “Wacky & totally unhinged” in an early morning tweet that came four days after the Farallon Capital founder released an ad that calls on lawmakers to kick Trump out of the Oval Office because he is mentally unstable.

“A Republican Congress once impeached a president for far less. And today, people in Congress and his own administration know that this President is a clear and present danger who is mentally unstable and armed with nuclear weapons,” Steyer says in the ad.

Trump also used his tweet to land a blow on Steyer, noting that he “never wins elections!” in which he gets involved.

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 typically does that via his checkbook — he reportedly spent $75 million with the goal of motivating the millennial generation to support “progressive causes.”

Trump’s tweets can push the limits of facts, but the president had a point Friday morning: Despite Steyer’s 2016 investment in Democratic candidates, it is Republicans who control both chambers on Capitol Hill and the White House.

Steyer’s campaign also targets specific Democratic members.

On Thursday night, he launched a Facebook ad campaign that urges constituents of House Minority Whip Steny H. Hoyer of Maryland to sign Steyer’s petition that the No. 2 House Democrat support removing Trump from office.

“Our Democratic leadership has a moral responsibility to do what’s right,” according to one of the ads, first reported by The Hill. “Add your name to my petition urging Whip Steny Hoyer to impeach Trump.”

Steyer may soon use hid deep pockets to fund his own campaign. He is mulling whether to challenge Sen. Dianne Feinstein in a California Democratic primary.

In another tweet, Trump congratulated Speaker Paul D. Ryan, R-Wisc., House Majority Leader Kevin McCarthy, R-Calif., and House Majority Whip Steve Scalise, R-La., for the House sending him a GOP budget resolution that allows a follow-on tax bill to pass the Senate with just 51 Republican vote.

“Now for biggest Tax Cuts,” the president proclaimed.

Congratulations to @SpeakerRyan, @GOPLeader, @SteveScalise and to the Republican Party on Budget passage yesterday. Now for biggest Tax Cuts

— Donald J. Trump (@realDonaldTrump) October 27, 2017