Trump.

President Trump’s legal team signaled earlier this week that they weren’t worried about the prospect of former Trump campaign chair Paul Manafort negotiating a plea deal with special counsel Robert Mueller — in fact, some lawyers close to the case suggested a plea deal could be beneficial for both Manafort and Trump.

But Harvard Law professor Alan Dershowitz, who has received a lot of flak over the last year for defending Trump at times despite being a self-described liberal, says Team Trump should be deeply concerned about Manafort’s agreement to fully cooperate with Mueller investigation, though he stressed that it’s unlikely Manafort would have any evidence that could lead to impeachment.

In an exchange reported by Mediaite, when MSNBC host and political correspondent Steve Kornacki asked Dershowitz Friday if Manafort’s cooperation agreement is “something the White House [should] be alarmed about right now,” Dershowitz answered emphatically.

“Well, of course they should be,” said the law professor, who later underscored that the only reason Mueller would be interested in flipping Manafort is if he believes he can get damaging information on Trump.

However, when it comes to the issue of impeachment, Dershowitz suggested, Manafort likely poses no real threat. “There’s nothing he can testify to that would probably lend weight to impeachment because he didn’t have close contact with President Trump while he was president,” he said.

He also emphasized that Manafort is not a credible witness, having just admitted to obstruction of justice and lying.

“What they are looking for is self-corroborating information that can be used against Trump,” Dershowitz explained. This validates what some have said from the beginning, he noted. Mueller isn’t interested in Manafort; he’s interested primarily in seeing “if they can make him sing and then there’s the possibility of him composing, elaborating on the story.”

Asked by Kornacki if this is really all about Trump, Dershowitz said, “There’s no doubt about that.”

Dershowitz also noted that “there’s no such thing as partial cooperation.” Having agreed to cooperate, Manafort must cooperate fully. In summary, he said later, this is a big victory for Mueller.