President Donald Trump. Carlos Barria/Reuters Attorney General Jeff Sessions and FBI special counsel Robert Mueller have in recent days entered the president's crosshairs.

Trump's team is reportedly looking for ways to discredit Mueller as he widens the Russia investigation.

Trump's maneuvers have once again raised the possibility that he could look to dismiss Mueller.

President Donald Trump has escalated his war against the Justice Department in recent days, placing his attorney general and the FBI's special counsel in his crosshairs as he becomes increasingly irritated by the expanding Russia investigation.

On Wednesday, Trump told The New York Times that he wouldn't have hired Attorney General Jeff Sessions if he had known Sessions would recuse himself from the investigation into Russia's election interference and whether his campaign team collaborated at all. He also attacked Deputy Attorney General Rod Rosenstein, suggesting a bias because Rosenstein was from Baltimore (though he is not). "There are very few Republicans in Baltimore, if any," Trump said.

A bombshell Washington Post report published Thursday night, and quickly echoed by a Times report, delineated clear battle lines: Trump and his legal team are searching for ways to discredit special counsel Robert Mueller and laying the groundwork to fire him.

Trump had been disturbed to learn that Mueller was digging into his business dealings and financial history, which Trump had previously suggested to The Times would be a "red line." Trump was particularly irked by the possibility that Mueller could access his tax returns, according to The Post.

"Talk about conflicts? But he was interviewing for the job," Trump told The Times, referring to the period when Mueller was being considered to replace FBI Director James Comey, whom Trump fired in May. "There were many other conflicts that I haven't said, but I will at some point."

Trump's legal team is reportedly looking into Mueller's previous working relationship with Comey and a dispute involving Trump's golf course as possible conflicts of interest. But experts say there is no evidence that Mueller has engaged in any inappropriate behavior that would warrant his removal.

An early conflict-of-interest concern involved his law firm's representation of some of the people caught up in the investigation, including Paul Manafort, Trump's former campaign chairman, and Jared Kushner, the president's son-in-law and senior adviser. That potential conflict was resolved by the Justice Department, which granted Mueller a waiver to move forward with the investigation, according to NPR.

Trump shook up his legal team on Thursday night, with some speculating that his lawyer Marc Kasowitz and legal spokesman Mark Corallo were ousted or shifted aside because they were uncomfortable with targeting Mueller.

Could Trump fire Mueller?

Experts in constitutional law say Trump could order Mueller's dismissal. But he could not fire him directly unless he ordered the repeal of the special-counsel regulations adopted in 1999, according to Neal Katyal, a former acting solicitor general who helped draft them.

But that would be an "extravagant" move, Katyal wrote in a Post column in May. If Trump wanted Mueller gone, it is more likely he would order Rosenstein to fire him. And even that would be shocking.

"Either of those actions was unthinkable to us back in 1999, for we understood that President Richard Nixon's attempt in this regard ultimately led to his downfall," Katyal wrote. He was alluding to the resignations of Attorney General Elliot Richardson and Deputy Attorney General William Ruckelshaus in October 1973 after they refused to follow Nixon's orders to fire Archibald Cox, the special prosecutor investigating Watergate.

Former Attorney General Eric Holder, who served in the Obama administration, said Thursday night that if Trump tried to "define or constrain" Mueller's investigation, it would create "issues of constitutional and criminal dimension."

Matt Miller, a Justice Department spokesman under President Barack Obama, said he realized after Trump fired Comey that "we all need to expand our imagination about what [Trump] might do to stop this investigation."

"I think it's clear that he will not let this investigation run its natural course without interfering in some fashion, and that is going to provoke a massive crisis for his presidency and the country," Miller said. "These leaks are probably the product of a lot of things, but one of them is Trump testing the boundaries of what he can get away with."

Could Trump pardon himself?

But undermining or firing Mueller would not be the only way Trump and his family could avoid legal troubles, if it came to that. According to The Post, Trump has been asking his legal team whether and how he could pardon himself — a legally ambiguous presidential power that, if invoked, would most likely reach the Supreme Court — and his children.

"Can Trump pardon himself? There's no precedent for this," Louis Seidman, a constitutional-law expert and professor at the Georgetown University Law Center, said in an email Friday. "Certainly as a matter of constitutional morality, it is very questionable."

Seidman said the real question was why Trump would even need to pardon himself, given the protection from prosecution his office affords him and the unlikelihood that he would be charged after leaving office.

"The more serious threat is that Trump would either pardon everyone else or fire Mueller," Seidman said. "My own sense, for what it's worth, is that this outcome is very likely."

But firing Mueller or issuing pardons "would be certain to ignite the kind of political firestorm that we haven't seen since the Saturday Night Massacre," he said, and Trump's political opponents would undoubtedly paint it as obstruction of justice.

"At that point, spineless Republicans would have to decide whether they are really going to stick with Trump," Seidman said. "What they decide will determine whether we still live in a constitutional democracy."

Miller agreed.

"If Republicans in Congress don't speak out against firing Mueller or pardoning members of his team, the lesson he'll take away is that [Trump] can get away with it — and that means he will almost certainly try it sooner or later," he said.

Democratic Sen. Mark Warner, the vice chairman of the Senate Intelligence Committee, said in a statement on Thursday that "pardoning any individuals who may have been involved" in Russia's election interference "would be crossing a fundamental line."

"The possibility that the president is considering pardons at this early stage in these ongoing investigations is extremely disturbing," Warner said.