President Donald Trump is perpetually simmering over the Russia investigation. But speculation that he might finally move to shut down the special counsel probe has intensified in recent days.

The White House has said Trump has the power to fire special counsel Robert Mueller outright, but the more likely scenario is that he instead fires Mueller’s boss, Deputy Attorney General Rod Rosenstein.

Rosenstein’s job security has, at many times, been tenuous. Rosenstein — whom Trump nominated for the job — took over the Trump-Russia investigation after Attorney General Jeff Sessions recused himself because of his meetings with Russians as a surrogate of the 2016 Trump campaign.

Rosenstein appointed Mueller shortly after the firing of FBI Director James Comey, and now oversees him. Rosenstein also reportedly signed off on the recent raid of Trump’s longtime personal lawyer and fixer Michael Cohen, a blow to Trump’s inner circle.

What’s followed are renewed rumors, amplified by Trump supporters, that Rosenstein’s days at the Justice Department are numbered.

If Rosenstein were fired, or if he quit, the spotlight would turn to Solicitor General Noel Francisco. Francisco is the next Senate-confirmed DOJ official in line, which means the Mueller investigation would drop to him. (The No. 3 in the department, Associate Attorney General Rachel Brand, resigned in February.)

Francisco has two options as Mueller’s new boss: He could keep the status quo and allow Mueller to continue the investigation. Or he could divert from Rosenstein’s course, potentially curtailing Mueller’s mandate or even shutting down the investigation.

Francisco, a prominent Republican lawyer, has some impressive conservative credentials. He clerked for Supreme Court Justice Antonin Scalia and worked in the Justice Department during the George W. Bush administration.

He’s also defended a broad interpretation of executive power — and he’s currently arguing a case before the Supreme Court that defends the president’s expansive power to fire executive branch officials. That case is unrelated to the Mueller probe. But Francisco’s argument, and his legal interpretations, offers some insight to the man who might be asked to fire Mueller.

Who is Noel Francisco?

The Senate confirmed Francisco as solicitor general, the lawyer who represents the government’s agenda before the Supreme Court, in September on a 50-47 party-line vote.

Francisco’s résumé also includes working on George W. Bush’s legal team in the 2000 Florida recount and, as a partner at Jones Day, representing former Virginia Gov. Bob McDonnell in his successful case before the Supreme Court that led to McDonnell’s corruption conviction being overturned.

Francisco has a sterling reputation as a conservative lawyer. He apparently wasn’t Trump’s first choice for the job; Chuck Cooper, a well-known litigator, withdrew from consideration. He did, however, serve as acting solicitor general as Trump conducted his search. Eventually, the president nominated Francisco, who then stepped aside until his Senate confirmation.

Francisco’s confirmation hearing was held the day after Trump fired FBI Director Comey, and the issue of “loyalty to the administration” was on the minds of some Democratic senators.

In a response to a written question on how he would maintain his independence from the White House, Francisco gave an anodyne answer: “If confirmed, I will provide the President, the White House, and any other entity that I am called upon to advise with candid and independent legal advice.”

Francisco also said he played no role in Comey’s firing, and reiterated that if confirmed, he would “provide candid, honest, and independent legal advice.”

Decoding Francisco’s views on executive power

Francisco’s past legal stances indicate he takes a pretty broad view of executive powers — and has expressed skepticism about the need for special counsels.

In 2007, he testified about his views on presidential power during a congressional inquiry into Bush’s politically motivated firing of nine US attorneys. The administration had been reluctant to turn over documents or let officials testify under oath on issues related to mass dismissal of US attorneys. Bush invoked executive privilege to defend his decision.

Francisco, who by then was in private practice, appeared before a House committee to defend the administration. As Mother Jones reports, he criticized the idea of appointing a special counsel to investigate the Bush administration over this scandal:

“I don’t think it would be appropriate for the Department of Justice to appoint” a special counsel, he testified, explaining that “my own personal belief is that when you hand these issues off to the career prosecutors in the public integrity sections in the US attorneys’ offices in the Department of Justice, those attorneys are generally better able to assess whether a case should be pursued.”

Francisco also argued for the expansiveness of executive power, saying that conversations between administration officials, even if Bush wasn’t actively involved, could be protected by executive privilege. He didn’t say executive privilege was absolute — but he basically said it was up to the court to decide: “What the courts have said is that in the context of a criminal investigation, if there is a sufficient showing of need, it can obviate the privilege.”

Francisco’s early tenure in the Trump administration indicates his positions haven’t shifted all that much. He is currently arguing a case before the Supreme Court that could have implications for the Mueller investigation. It involves a narrow issue of how the Securities and Exchange Commission (SEC) administrative law judges are hired. But as the Los Angeles Times reported last weekend, Francisco has stepped in and asked the Court to decide on a much larger question of the president’s constitutional authority to not just hire officials but fire them too:

Francisco points to two provisions of the Constitution as giving the president very broad authority. One says the president shall appoint ambassadors, judges and “all other officers of United States.” The other says the president “shall take care that the laws be faithfully executed.” ”The president’s constitutional responsibility to faithfully execute the laws requires adequate authority to remove subordinate officers,” Francisco told the court in February. “The framers understood the close connection between the president’s ability to discharge his responsibilities as head of the executive branch and his control over its personnel. … The president’s ability to execute the law is thus inextricably linked to his authority to hold his subordinates accountable for their conduct.”

Francisco is basically saying the Constitution gives the president the ability to dismiss all officials who have power under the executive branch. That could, most conspicuously, give Trump a legal way to oust Mueller.

The Supreme Court will likely judge the case very narrowly on the question raised about the status of SEC administrative law judges. But it’s telling that the administration is taking this stance and that Francisco, as the solicitor general, is making these arguments before the Court.

Francisco’s approach to executive power doesn’t mean he’ll take over and fire Mueller if Rosenstein is ousted, or even rein in Mueller’s mandate — but it does hint that he might be more sympathetic to the Trump administration’s stance.

Still, he did dine with Rosenstein and Attorney General Sessions in March shortly after Trump antagonized Sessions for, in his view, not doing enough about the FBI’s handling of the surveillance of former Trump campaign adviser Carter Page. (Recall the claims in the Nunes memo.)

The dinner, coming as it did on the heels of the president viciously and publicly attacking his attorney general, seemed symbolic of a united front against the onslaught. Then again, all three, Francisco included, could be fired by Trump at any time.