The Editorial Board

USA TODAY

When Robert Mueller was appointed in May to oversee the investigation into possible Russian interference in the 2016 campaign, he was universally praised as the perfect choice. Former House speaker Newt Gingrich, a vocal supporter of President Trump, tweeted that Mueller's "reputation is impeccable for honesty and integrity."

And so it is. Amid the contemptible efforts to discredit Mueller's investigation, let's pause for a moment to remember who he is: A Republican. A Marine Corps veteran who earned a Bronze Star for valor and Purple Heart for a gunshot wound to his thigh during combat in Vietnam. A longtime federal prosecutor before President George W. Bush nominated him to direct the FBI in 2001 and the Senate unanimously confirmed him.

Mueller took office a week before Sept. 11 and led the bureau during the height of the war on terrorism, his agents tirelessly circumventing additional attacks. Mueller was so highly respected that he was asked to stay on under President Obama.

REP. BIGGS:Mr. Mueller, end your witch hunt

Yet as the Russia investigation gathered steam with charges brought against four former Trump campaign officials in recent months, a coterie of Republican congressmen, joined by commentators on Fox News and other Trump-friendly media outlets, have started calling for Mueller's head. Rarely has the American public been suddenly asked to revile a public figure once so widely revered.

"We are at risk of a coup d'etat in this country," Rep. Matt Gaetz, R-Fla., warned ominously on the House floor in November, using the sort of irresponsible language that could well inflame homegrown terrorists.

The special counsel's ostensible crime? Members of his staff — like every other American — hold political views in their private lives. In fact, nothing in the FBI code of ethics requires agents to be cleansed of political leanings. The fair investigation of political figures they might personally dislike is nothing new. Just the same, when Mueller learned last summer that one of his investigators had tweeted to another FBI employee that Trump is an "idiot," the investigator was immediately reassigned.

The Justice Department's inspector general is looking into any issue of bias at the FBI and will produce a report in the months ahead. In the meantime, there is zero evidence that Mueller has done anything wrong and every indication he is making headway into the vital issue of foreign intrusion into American elections.

The factions calling the special counsel's fairness into question are laying the groundwork for either undermining Mueller's conclusions or firing him. To pre-empt his possible removal, Congress should promptly pass bipartisan legislation to provide greater protections for the special counsel.

Where logic falls away amid the odious campaign to tarnish Mueller and his investigators — bolstered Tuesday by Trump's latest "FBI TAINTED" tweet — is with the prospect that the president might well be innocent of wrongdoing.

Imagine if that's true. If the Russia story is truly "fake news" and a "witch hunt," as the president and his minions insist, why would they sling mud at the very people and institutions that would place their valuable imprimatur on such a conclusion? Why, you have to wonder, are they so worried about what Mueller's investigation might reveal?

If you can't see this reader poll, please refresh your page.