SACRAMENTO, Calif. (AP) — California billionaire Tom Steyer announced Friday that he will dump at least $10 million into a national television advertising campaign calling for President Donald Trump's impeachment.

In the ad, Steyer argues Trump should be ousted from office because he has edged the country toward nuclear war, obstructed justice at the FBI and threatened to shut down news organizations he does not like. He urges viewers to call their members of Congress and tell them to bring articles of impeachment.

"People in Congress and his own administration know this president is a clear and present danger who is mentally unstable and armed with nuclear weapons," Steyer says in the ad. "And they do nothing."

Steyer plans to spend eight figures to air the television ads nationally, but he would not give an exact amount. His investment comes as he considers running against U.S. Sen. Dianne Feinstein, a fellow Democrat, and as Democrats in Washington argue over whether efforts to impeach Trump are smart or worthwhile.

"If Democrats want to appease the far left and their liberal mega-donors by supporting a baseless, radical effort that the vast majority of Americans disagree with, then have at it," said Michael Ahrens, a spokesman for the Republican National Committee.

Republicans will focus on "issues voters actually care about," such as the economy and cutting taxes, he said.

The White House did not immediately respond to a request for comment.

Steyer also said he will spend seven figures on an accompanying digital ad campaign.

An impeachment resolution brought last week by Democratic U.S. Rep. Al Green of Texas died before coming up for a vote. Green has vowed to try again.

But Democrats such as House Minority Leader Nancy Pelosi of California think impeachment attempts are not worthwhile because they will fail in the Republican-led Congress and could energize GOP voters heading into the next election.

Steyer has poured his wealth into a variety of political efforts, mostly focused on stopping climate change.