Billionaire Tom Steyer speaking at a rally calling for the impeachment of President Donald Trump, Tuesday, in San Francisco, Calif. (Justin Sullivan/Getty Images)

The progressive activist has launched an eight-figure television campaign that aims to build momentum for Trump’s impeachment.

President Donald Trump took aim at billionaire Democratic donor Tom Steyer on Friday in the wake of the progressive hedge fund manager launching an ad campaign pushing for Trump's impeachment.

The ad aired on Fox News – which the president has been known to watch – during the channel's morning "Fox & Friends" programming.

"Wacky & totally unhinged Tom Steyer, who has been fighting me and my Make America Great Again agenda from beginning, never wins elections!" Trump tweeted, amid other messages congratulating "Fox & Friends" on a "really great job and show" and wishing Trump-supporting singer Joy Villa well in a potential political run.

Steyer, who spent some $90 million supporting 2016 Democratic candidates, launched the eight-figure television campaign last week. In his TV spot, he makes a case for Trump's impeachment, and is backing the ad with a seven-figure social media campaign, according to The Washington Post.

"A Republican Congress once impeached a president for far less, yet today, people in Congress and his own administration know that this president is a clear and present danger, who's mentally unstable and armed with nuclear weapons, and they do nothing," Steyer says in the ad.

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The ad directs viewers to a website, NeedToImpeach.com, where they can sign on to support Trump's impeachment.

"Donald Trump has brought us to the brink of nuclear war, obstructed justice, and taken money from foreign governments," the site says. "We need to impeach this dangerous president."

The campaign is not being funded through Steyer's political organization, NextGen America, but rather by Steyer personally.