It's disturbing enough that Republican leaders have been willing to turn a blind eye to the growing list of President Trump's associates ensnared in the Russian imbroglio, including Senate Majority Leader Mitch McConnell and House Speaker Paul Ryan. But House Intelligence Committee Chairman Devin Nunes, instead of properly leading his panel's investigation, has taken its credibility to a new low.

Nunes looked more like a Keystone Cop last week as he tried to lend support to Trump by claiming he had reviewed documents indicating members of the president's transition team — and perhaps even Trump — might have been "incidentally" caught up in legal surveillance by U.S. spy agencies following the election.

After getting this explosive information, Nunes held a press conference outside the White House and then briefed Trump. He didn't bother to first share the information with other committee members. That's like an FBI agent holding a news conference about an ongoing investigation and then briefing a possible suspect.

Nunes' unheard-of moves prompted Rep. Adam Schiff, the intelligence committee's top Democrat, to question whether the California congressman was a "surrogate of the White House." Nunes sure acted like he was Trump's new lap dog. But as it seems to be with almost everything that involves this drama-filled White House, the story does not end there.

It turns out that Nunes received his dubious surveillance information during a meeting on the grounds of the White House. That has prompted speculation that someone in the administration gave Nunes the information to deflect attention from FBI Director James Comey's earlier testimony that the federal agency has been conducting a criminal investigation since July into whether Trump's campaign had colluded with Russia to influence the 2016 election.

Comey also testified there was no evidence that President Barack Obama wiretapped Trump facilities during the campaign — as the president has claimed.

The revelation that Nunes got his information about the FBI's surveillance during a visit to the White House has prompted Democrats, and even some Republicans, to call for him to recuse himself from the committee's investigation. He has rejected calls for his recusal, but canceled scheduled hearings.

It's clear that Nunes, who served on Trump's transition team, is too close to the president for the public to have confidence that he can lead an impartial inquiry.  Nunes has tainted the probe and should recuse himself.

An even better option than the charade the House investigation appears to be would be for the deputy attorney general to appoint a special counsel to investigate Trump's alleged Russian ties. That task can't be left to Attorney General Jeff Sessions Sessions, who was forced to recuse himself from any investigation into Trump's campaign because he twice met with Russia's ambassador while advising Trump.

The list of Trump associates who met with Russian officials, including several who lied about it, raises serious concerns. The president could ease some of the angst about his coziness with Russia by simply releasing his tax returns. Otherwise, that dark cloud over the White House will hobble his presidency.