(Andrew Harnik/Associated Press)

From the moment a special counsel was appointed to investigate Russian meddling in the 2016 election and the Trump campaign’s potential collusion with that meddling, it was inevitable that it would become a target of Republican attacks. That’s just how things work: As soon as it became clear that the investigation wouldn’t simply exonerate the president, his allies in Congress and the media would try to disparage and discredit it to minimize the damage it might do to the administration.

But at this point, they have nearly lost their minds. And it’s precisely because, from all appearances, Robert S. Mueller III is going about his work methodically and professionally, and is getting closer and closer to the Oval Office. If Mueller really were some kind of partisan hack launching a witch hunt, Donald Trump and the rest of the GOP wouldn’t have all that much to fear.

But they do, and their reaction is positively unhinged. To take just one example, let’s look at this appearance yesterday on Fox News by Tom Fitton, head of the conservative organization Judicial Watch:

That is not just the lunatic ravings of one extremist. It is fast on its way to becoming the position of many in the Republican Party — not that we should shut down the FBI, but that the Bureau has become a hopelessly corrupted outpost of anti-Trump subversion, expressed most fully in Mueller’s investigation, which not only must be shut down but which should then be targeted by

another

special counsel appointed to investigate Mueller.

This hysterical campaign Republicans are now waging against Mueller and the FBI is being hung mostly on the fact that an agent named Peter Strzok, who had been working for Mueller, sent texts during the 2016 campaign to his girlfriend, a Justice Department attorney, in which they said uncomplimentary things about Trump. As soon as Mueller discovered that, he had Strzok reassigned.

This week, in a highly unusual decision, the Justice Department showed reporters many of those texts, so they would then be disseminated to the public. They tell us nothing about Mueller’s investigation, since they were sent before there was any investigation. All they tell us, in some colorful language, is that this FBI agent found Trump to be a dangerous fool, an opinion which by sheer coincidence happens to be shared by many people who work for Trump today.

Everyone agrees that it’s important that Mueller’s investigation be conducted with the highest standards, in which all the participants examine evidence objectively, pursue potential crimes to wherever they lead, and implicate only those whose actions were genuinely problematic or criminal. But it’s important that we step back and grasp the underlying argument Republicans are making right now. They seem to be saying that if an investigator is revealed to have political leanings, then that investigator is by definition warping the investigation in service of his politics. Not only that, even if he is removed from the investigation, it is forever tainted.

Republicans are not saying that Strzok actually committed any kind of misconduct during the time he was working for Mueller, because there is no evidence to suggest he did. Instead, some of them are saying that the very fact that we know this guy who used to work for Mueller didn’t like Donald Trump means that the investigation is hopelessly compromised. Because of this, some Trump allies say, it must therefore be shut down.

But if that were true, then it would be impossible to run any investigation of any president. The fact that Mueller is himself a Republican would mean that he is biased and couldn’t be objective when investigating a Republican president. But a Democratic prosecutor would be also biased against a Republican president, just in the other direction. So investigations could only be staffed by people who had no political leanings or opinions at all.

Here’s one thing we haven’t seen: All the text messages sent about Donald Trump or Hillary Clinton by every other FBI agent. Because if we did, I’m pretty sure that they’d weigh heavily in Trump’s favor. That’s because the FBI is an extremely conservative institution staffed by people who tend to be pretty conservative themselves. It spent much of its history targeting suspected communists and civil rights activists and anti-war activists and people who objected to U.S. foreign policy.

In fact, if we want to find evidence that FBI agents not only had opinions about the presidential candidates but took action to influence the campaign, we don’t have to look far. As the Guardian reported just before the election, “Deep antipathy to Hillary Clinton exists within the FBI, multiple bureau sources have told the Guardian, spurring a rapid series of leaks damaging to her campaign just days before the election.” As one agent put it, “The FBI is Trumpland.”

Needless to say, as obvious as that was at the time, Republicans were not bothered, because they plainly believe that investigations of Republican presidents must be run and staffed only by Republicans sympathetic to that president, and likewise, investigations of Democratic presidents must be run and staffed only by, that’s right, Republicans unsympathetic to that president.

And that has been the tradition. Lawrence Walsh, who investigated the Iran-Contra affair, was a Republican. Kenneth Starr, who tirelessly investigated the contents and activities of what was in Bill Clinton’s pants, was a Republican. Mueller is a Republican.

Which isn’t necessarily a problem, nor is it a problem that people working for Mueller have their own thoughts about politics. Republicans have angrily pointed out that a few people on Mueller’s team made contributions to Democrats. But as Rep. Ted Lieu (D-Calif.) pointed out yesterday, FBI Director Christopher A. Wray has made $39,000 in political contributions, all to Republicans, and Associate Attorney General Rachel Brand, who ranks just below Deputy Attorney General Rod J. Rosenstein, has made $37,000 in contributions to Republicans. Does that mean that the FBI and the Justice Department are fatally biased in Donald Trump’s favor when it comes to the investigations they pursue? Of course not.

In the end, what matters is what Robert Mueller’s investigation produces. So far, there hasn’t been a shred of evidence that it has been anything but professional. Perhaps the indictments and plea bargains he has obtained so far will be the end of the story, and he’ll conclude that there was no further wrongdoing, particularly on the president’s part. But the possibility that he’ll find a great deal more — and present it with unimpeachable evidence — is precisely what has Republicans in such a panic.