When a recording leaked of Mr. Bloomberg defending stop-and-frisk in New York, Andre Fields of the liberal voting-rights group Fair Fight Action rushed out a tweet hitting him as a “true terrorist” but promptly deleted it. Fair Fight Action had received $5 million in funding from Mr. Bloomberg. Three members of the Congressional Black Caucus helped out with timely endorsements of a man who spent at least $90 million on House Democratic races in the last 19 months.

New York Times columnist Tom Friedman on Wednesday joined in with 1,500 words implying that other Democratic candidates should make way for Mr. Bloomberg. He ended his piece with a disclosure that his wife’s charity was supported with Bloomberg donations.

Mr. Bloomberg has said he will spend $1 billion through Election Day. If so, he will have to curb his outlays to meet his target. At $344 million, he’s already spent more on advertising than the Clinton and Trump campaigns did in all of 2016.

I wouldn’t put it the way his left-wing critics do—that he’s trying to buy the nomination or the presidency. He’s trying to buy the Democratic Party elite. He’s distorting the incentives of activists, officials and campaign fixers who suddenly are thinking less about a presidential victory and more about the Bloomberg gravy train.