President Donald Trump attacked special counsel Robert Mueller’s Russia investigation again on Wednesday morning. But instead of just repeating his claim that he didn’t collude with Russia, Trump is now targeting the man leading the probe.

Trump has condemned Mueller’s investigation into whether his campaign colluded with Russia during the 2016 presidential election many times in the past, but he hadn’t specifically mentioned Mueller’s name until March. And on Wednesday, Trump tweeted a pointed ad hominem attack, saying that Mueller “is most conflicted of all,” and accused Mueller of going “crazy” because there’s “no collusion.”

Much of the bad blood with Russia is caused by the Fake & Corrupt Russia Investigation, headed up by the all Democrat loyalists, or people that worked for Obama. Mueller is most conflicted of all (except Rosenstein who signed FISA & Comey letter). No Collusion, so they go crazy! — Donald J. Trump (@realDonaldTrump) April 11, 2018

Trump also criticized Deputy Attorney General Rod Rosenstein in his tweets. Both men were targets of the president’s fiery remarks on Monday after the FBI raided the office and hotel room of Trump’s personal lawyer Michael Cohen.

The personal attacks coincide with reports that Trump is seriously considering firing Rosenstein or Mueller, or possibly even both, after Monday’s raid.

Lending credence to this theory, the White House defended Trump’s right to fire Mueller on Tuesday. White House press secretary Sarah Huckabee Sanders said that Trump had “been advised that the president certainly has the power” to fire Mueller.

Trump’s attacks on the Russia probe are getting personal

It’s important to note that Trump’s lawyers have repeatedly told him not to mention Mueller by name, and Trump held off for almost a year after Mueller started his investigation in early 2017. But on March 18, Trump mentioned Mueller by name in a tweet.

“Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and Zero Republicans?” Trump wrote.

Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and Zero Republicans? Another Dem recently added...does anyone think this is fair? And yet, there is NO COLLUSION! — Donald J. Trump (@realDonaldTrump) March 18, 2018

He was less cautious in his previous comments about Rosenstein. In a July interview with the New York Times, Trump implied that Rosenstein is biased because he’s from Baltimore.

“There are very few Republicans in Baltimore, if any,” Trump said.

But Wednesday’s tweet is different since it’s not just an implication of bias — it’s a direct accusation of a conflict of interest.

The sudden surge in personal attacks against Rosenstein and Mueller seems like it’s coming in response to a Justice Department investigation into Cohen for payments he made to women who say they had affairs with Trump. Cohen paid them to keep quiet about their claims before the election, which may have broken campaign donation law or money transfer rules.

Mueller brought evidence of potential crimes to Rosenstein, who approved the search of Cohen’s documents, likely putting them both in Trump’s crosshairs.

In Monday’s tirade to reporters, Trump said that the investigation is an “attack on our country” and mused about firing Mueller.

“Why don’t I just fire Mueller,” Trump said, repeating a reporter’s question. “We’ll see what happens.”

Trump has aggressively criticized the Russia investigation since its inception, repeatedly calling it a “witch hunt” and saying that he was innocent of any crimes. But this new, personal twist implies that he might be gearing up to fire the men leading the investigation.