Matt Whitaker’s unprecedented appointment to acting Attorney General has been slammed by legal experts on both sides of the aisle as unconstitutional and solely aimed at quashing special counsel Robert Mueller’s Russia probe.

On Wednesday, President Trump appeared to confirm at least part of his critics’ fears, in a revealing, off-the-cuff interview with the conservative website Daily Caller.

Asked for his thoughts about the new AG, Trump veered directly into an assault on Mueller.

Trump said: “I knew him [Whitaker] only as he pertained, you know, as he was with Jeff Sessions. And, you know, look, as far as I’m concerned this is an investigation that should have never been brought. It should have never been had. It’s something that should have never been brought. It’s an illegal investigation. And you know, it’s very interesting because when you talk about not Senate confirmed, well, Mueller’s not Senate confirmed.”

Trump’s latest comments could add further evidence to a potential accusation that he obstructed justice — a question Mueller has also been tasked with investigating — according to three legal experts who spoke with VICE News.

“As usual, Trump’s candor is not his best friend, in terms of his legal liability,” said Jens David Ohlin, vice deal of Cornell Law School. “Trump is just flat-out admitting here that he views the investigation as illegal. It’s pretty disturbing for him to be so open about it.”

The comments appear highly revealing, former prosecutors told VICE News.

“As usual, Trump’s candor is not his best friend, in terms of his legal liability.”

“This interview is another indication of his state of mind, showing clearly that he disfavors the Mueller investigation, and that he has taken steps to install people who could impede the probe,” said Seth Waxman, a former federal prosecutor from Washington DC. “This is definitely another potential key piece of evidence that could be used by Mueller to show the intent, pattern and practice of attempting to obstruct.”

Taken all together, Trump’s actions and statements with regard to the Russia investigation appear “obstructive,” said Mimi Rocah, a former prosecutor with the Southern District of New York.

“Is it evidence of the crime of obstruction? It could be, if you put it together with the whole pattern of things that he does,” Rocah said.

Trump has denied knowing Whitaker, despite the pair’s numerous interactions before the announcement, but the new acting AG's sudden ascension to the nation’s top cop paints a picture of a powerful defender of the president, who's broadsides against the probe quickly caught the president's attention.

Before joining the Department of Justice in late 2017 as Sessions’ chief of staff, Whitaker made a series of public comments that were openly hostile to the Russia investigation that he now oversees.

In one CNN appearance, he pointed out that Trump could quash Mueller, without going through the drama of firing him, by replacing Sessions with a new appointment who might simply reduce Mueller’s budget to a bare minimum.

“Any prosecutor who takes that position on meeting with foreign agents or officials to gather dirt on a political opponent is an idiot.”

Whitaker has also expressed approval of a decision by top brass at the Trump campaign to take a meeting with a Russian lawyer billed as bringing dirt on Clinton.

“I’m appalled,” said Gene Rossi, a former prosecutor from the Eastern District of Virginia. “Any prosecutor who takes that position on meeting with foreign agents or officials to gather dirt on a political opponent is an idiot.”

HERE’S WHAT TRUMP SAID:

THE DAILY CALLER: Sure. Could you tell us where your thinking is currently on the attorney general position? I know you’re happy with Matthew Whitaker, do you have any names? Chris Christie —

TRUMP: Matthew Whitaker is a very respected man. He’s — and he’s, very importantly, he’s respected within DOJ. I heard he got a very good decision, I haven’t seen it. Kellyanne, did I hear that?

WHITE HOUSE ADVISER KELLYANNE CONWAY: 20 pages.

TRUMP: A 20-page?

THE DAILY CALLER: It just came out right before this, sir.

TRUMP: Well, I heard it was a very strong opinion. Uh, which is good. But [Whitaker] is just somebody that’s very respected.

I knew him only as he pertained, you know, as he was with Jeff Sessions. And, you know, look, as far as I’m concerned this is an investigation that should have never been brought. It should have never been had. It’s something that should have never been brought. It’s an illegal investigation. And you know, it’s very interesting because when you talk about not Senate confirmed, well, Mueller’s not Senate confirmed.

THE DAILY CALLER: Right.

TRUMP: He’s heading this whole big thing, he’s not Senate confirmed. So anyway, I have a lot of respect for Matt Whitaker, based primarily on reputation. And I think he’s really — I think a lot of people are starting to come out very much in favor of him during this period of time.

THE DAILY CALLER: What about who will eventually replace him, sir?

TRUMP: Well, I’m looking at a lot of people. I have been called by so many people wanting that job. We have some great people. In the meantime, I think Matt’s going to do a fantastic job.