Former New York Mayor Mike Bloomberg plans to donate $10 million to help shore up vulnerable House Democrats being targeted by allies of President Trump because of the ongoing impeachment inquiry.

A spokesman for Bloomberg confirmed the spending — an announcement that comes as the former mayor plans to spend today picking up endorsements for his presidential bid in California. The mayor of Stockton, California, is set to endorse Bloomberg, a day after the mayor of San José, a former supporter of the presidential bid of Senator Kamala Harris, Democrat of California, signed on to serve as his California co-chairman.

Decisions about how to spend the $10 million will be handled by House Majority PAC, a campaign arm of the House Democratic caucus, the Bloomberg spokesman confirmed.

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Robby Mook, president of House Majority PAC, said that with Bloomberg's donation, "we'll be able to ensure voters understand how their Democratic House majority is working on the issues that matter, like protecting access to affordable health care and reducing the cost of prescription drugs."

Mook is also a CBS News political contributor.

In an interview with "CBS This Morning" last week, asked by co-host Gayle King whether Mr. Trump should be impeached, Bloomberg responded, "I think it's a very serious thing but it — and I was before opposed to it but after looking at all of the evidence, I think yes. Sad, but yes," Bloomberg said.

His donation so far pales in comparison to the $110 million Bloomberg spent through his own PAC to help Democratic congressional candidates last year, although it's still early in the campaign cycle. In the 2018 midterms, 21 of the 24 candidates he supported won their races, a senior Bloomberg aide noted.

He is also spending millions of his own dollars to run ads against President Trump in several swing states — ads separate from his own campaign.

House Speaker Nancy Pelosi welcomed the support, praising him in a statement as a "critical ally in helping Democrats" win the majority in 2018.

News of the donation was first reported by The Washington Post.