Billionaire investor Bill Ackman said he plans to donate $1 million to a political action committee backing Rep. Dean Phillips (Minn.) — the Democrat who launched a long-shot primary challenge to President Biden last year.

In a lengthy post on X, the platform formerly known as Twitter, Ackman said Phillips would be “a truly outstanding President of the United States,” adding that he believes he has a “credible path” to the nomination. He said he will donate $1 million to the We Deserve Better PAC this week.

“On Tuesday, I am wiring $1 million to wedeserve.org, a political action committee that supports Dean’s run. This is by far the largest investment I have ever made in someone running for office, and I am making this investment at a high-risk, but critically important moment for his campaign,” Ackman wrote on X.

Phillips is trailing far behind Biden in the poll as he pushes forward with his campaign for the nomination. According to RealClearPolitics’s polling average of the Democratic primary, Biden is polling at nearly 70 percent support, followed by author Marianne Williamson at nearly 8 percent and Phillips at about 3 percent.

Ackman said Phillips has a way forward in the primary if he does well in New Hampshire. He also said Biden’s “numbers are only going to get worse as he ages.”

“As Dean rises in the polls and Biden deteriorates, the Democratic party is going to have to choose a candidate that can beat the Republican nominee. If by then, as I expect, Dean is polling substantially better than Biden against Trump, I predict that the party will choose Dean Phillips over Biden,” he wrote. “The party will have no choice.”

Biden will not appear on the state’s Democratic primary ballot because the Democratic National Committee is not recognizing the primary this year. Despite Biden not being on the ballot, a recent poll found that nearly 64 percent of Democrats said they would vote for Biden as a write-in candidate over someone else.

Ackman had previously signaled support for Phillips’s bid for the White House, saying he was “impressed” by the congressman last year. He also said it was time for Biden to “step aside” in the primary.

“I think Biden’s done a lot of good things. But I think his legacy will not [be] a good one if he is the nominee,” Ackman said in an interview in November with Bloomberg Television’s “The David Rubenstein Show: Peer-to-Peer Conversations.” “I do think the right thing for Biden to do is step aside, and to say he’s not going to run, and create the opportunity for some competition.”