The appointment of former FBI Director Robert Mueller to serve as special counsel investigating matters related to Russia and the 2016 presidential campaign served to effectively quell the firestorm of criticism launched by Donald Trump's decision to fire Mueller’s successor at the FBI. But what if Trump fires Mueller, too, as is his right under the law?

That’s exactly what a growing chorus of voices in pro-Trump media are arguing that he should do, with former House Speaker and leading Trump sycophant Newt Gingrich leading the charge.

Republicans are delusional if they think the special counsel is going to be fair. Look who he is hiring.check fec reports. Time to rethink. — Newt Gingrich (@newtgingrich) June 12, 2017

It seems that the consensus that there’s a problem with Mueller is somewhat in advance of the consensus on what the problem exactly is. But Trump-friendly pundits are throwing a few different ideas out there.

Any such move would, of course, be politically explosive and draw direct parallels to Richard Nixon’s conduct. But if Republicans on Capitol Hill are willing to go along with it, there’s nobody else out there who can actually stop Trump.

There’s nothing to investigate

Ann Coulter offered the argument that since Comey testified that Trump was not personally under investigation, there is nothing to investigate, and thus no need for a special counsel.

Now that we FINALLY got Comey to admit Trump not under investigation, Sessions should fire Mueller. Why do we need a special counsel now? — Ann Coulter (@AnnCoulter) June 11, 2017

The problem here is that even if the president is personally innocent of any wrongdoing, there can still be significant legal jeopardy for people in his orbit.

Former National Security Adviser Michael Flynn appears to be in hot water regarding his secret sources of foreign income, Attorney General Jeff Sessions made false statements under oath regarding his meetings with Russian Ambassador Sergey Kislyak, senior adviser Jared Kushner seems to have made false sworn statements on his security clearance paperwork regarding meeting an executive at a Russian bank that’s widely seen as a front for Russian intelligence, and Trump campaign chair Paul Manafort is facing questions about possible money laundering.

That’s all the kind of thing you might want investigated by someone outside the normal Department of Justice chain of command.

There’s a conflict of interest

Byron York of the Washington Examiner floats a different account: Mueller can’t investigate Comey because they used to work together.

“Comey,” York writes, “is a good friend of special counsel Robert Mueller — such a good friend, for about 15 years now, that the two men have been described as ‘brothers in arms.’”

The idea that Mueller is unfit to investigate a Republican administration because he served alongside Comey as a high-level appointee in the previous Republican administration is too ridiculous for York to outright endorse, so instead he frames his article as a reporting mission in which he consults with experts on the question of whether or not there’s a conflict of interest. York is unable to find a single person willing to go on the record as supporting his conflict of interest theory.

But he does find four anonymous lawyers, three of whom worked at one point for the Justice Department, to say it’s inappropriate for Mueller to head an investigation that involves Comey as a witness.

Mueller’s team is biased

Gingrich’s argument is more straightforward: Mueller is biased and unfair.

This is a bit of a hard sell. Mueller won a bronze star as a Marine in the Vietnam War. Ronald Reagan appointed him as US attorney for Massachusetts, George H.W. Bush appointed him an assistant attorney general, and George W. Bush as deputy attorney general and then later FBI director. He’s not a particularly partisan figure (he also served a couple of years as a Clinton-appointed US attorney, and Barack Obama extended his term as FBI director by two years,) but he’s generally regarded as a Republican, and has received Senate-confirmed appointments by each of the past five presidents.

But Gingrich's suggestion that we “look at who he is hiring” and “check FEC reports” hints at the broad outline of a case.

Andrew Weissmann, the head of the DOJ Criminal Division’s fraud section, for example, has gone to work for Mueller. That seems natural enough since Weissmann served as general counsel of the FBI when Mueller was director. But FEC reports show that Weissmann donated about $2,300 to the Obama/Biden campaign in 2008.

Jeannie Rhee, a former Justice Department lawyer who’s now a colleague of Mueller’s at Wilmer Hale donated to Obama, to Hillary Clinton, and to a few of Democratic senate candidates over the years.

James Quarles, a Watergate prosecutor and longtime Wilmer Hale attorney, was also a donor to Obama in 2008 and Clinton in 2016.

An explosive move, but a tempting one

Obviously, to fire a well-regarded special prosecutor who is investigating your own administration would be an explosive political move.

When Richard Nixon did this in the Saturday Night Massacre it was a major scandal that, in many respects, kicked the Watergate investigation into overdrive. And, indeed, it was the political backlash to firing Comey that saddled Trump with the Mueller investigation in the first place. Prudent counselors might advise him that firing Mueller will only serve to further exacerbate his problems.

On the other hand, while firing Comey was not exactly well-received on Capitol Hill, the vast majority of congressional Republicans were eager to rally around the idea that Trump was within his legal rights to fire the FBI director. One clear takeaway from Comey’s public testimony last week is that congressional Republicans do not believe that asking an FBI director to stymie an investigation, then firing him when he doesn’t do it, then lying to the public about why you fired him constitutes obstruction of justice or abuse of power in the relevant sense.

Given that standard, they might well conclude that firing Mueller is okay too. Trump’s legal authority to do this, after all, is perfectly clear. The only check is political backlash on Capitol Hill, where Republicans hold majorities in both houses and have thus far shown little inclination to check Trump.

Last but by no means least, one advantage Trump has in Russia-related decision-making is that he knows more than either his allies or his antagonists in Congress about what the underlying facts of the case are. Trump is in a unique position to evaluate whether the political costs of a cover-up exceed the political costs of a thorough investigation. In the case of, for example, his still-secret tax returns and personal finances, Trump has decided that the cover-up is the wiser path — and it’s certainly possible he’ll reach the same conclusion with regard to Mueller.