President Trump slammed liberal billionaire Tom Steyer on Friday as “wacky” and “totally unhinged,” after he launched a multi-million dollar 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!” Trump tweeted early Friday.

Steyer, a staunch environmentalist and Trump critic, launched a $10 million national campaign ad calling for the president’s impeachment last week.

The one-minute ad calls Trump “mentally unstable [and] armed with nuclear weapons.” It accuses the president of obstructing justice in his firing of former FBI Director James Comey, violating the Constitution, taking money from foreign governments and threatening to shut down press organizations.

“Like you, I’m a citizen who knows it’s up to us to do something,” Steyer said in the ad, sending viewers to the website NeedToImpeach.com.

An aide to Steyer told Forbes that the television ad buy would be accompanied by a multi-million dollar digital advertising campaign.

According to OpenSecrets.org, Steyer donated to Hillary Clinton; Rep. Maxine Waters, D-Calif., who has repeatedly called for Trump’s impeachment; and Democratic candidates for Senate.

Congressional Democrats like Reps. Brad Sherman of California, Al Green of Texas and Waters also have called for the president’s impeachment.

Steyer and his super PAC, back in 2014, reportedly sought to raise $100 million to elect allies in the climate change fight – though they fell short of that goal, Steyer later denied setting it and Republicans went on to gain control of the Senate and pick up seats in the House and local races.