Opinion: It’s not exactly tough to believe the worst about Devin Nunes. But should we on Ukraine?

Democrats are pressing the House Ethics Committee to look into assertions by CNN and the Daily Beast that Rep. Devin Nunes (R-Tulare), the top Republican on the House Intelligence Committee and a blinkered defender of President Trump, worked with an indicted Ukrainian American to gather dirt on former Vice President Joe Biden in Europe at taxpayer expense.

But as tempting as it may be to believe the worst about Nunes, given his furious spewing of unsubstantiated allegations during the impeachment hearings, people need to look at the person behind the allegations, Lev Parnas, and his supposed source, former top Ukrainian prosecutor Victor Shokin.

Parnas is one of two Soviet emigres who worked with Trump’s personal lawyer, former New York Mayor Rudolph Giuliani, to advance several narratives in Ukraine that were designed to help Trump. These include the notions that Ukrainians meddled in the 2016 campaign on behalf of Hillary Clinton and that then-Vice President Joe Biden’s efforts to get Ukraine to crack down on Shokin and other officials accused of corruption were a smokescreen designed to protect his son, who held a lucrative board seat on a Ukrainian energy company also suspected of corruption.

So much corruption, it’s hard to keep track of it all. And I almost forgot: Parnas himself is under indictment in the United States for allegedly funneling foreign contributions into U.S. political campaigns.

According to the Daily Beast, attorney Ed MacMahon said Parnas “helped arrange meetings and calls in Europe” for Nunes and his staff late last year to “help Nunes’ investigative work,” although the nature of the investigations was not disclosed. And according to CNN, lawyer Joseph A. Bondy said Parnas “is willing to tell Congress about meetings [Nunes] had in Vienna last year with a former Ukrainian prosecutor [Shokin] to discuss digging up dirt on Joe Biden.”

The Daily Beast backed up its reporting with receipts: “Congressional records show Nunes traveled to Europe from Nov. 30 to Dec. 3, 2018. Three of his aides — [Derek] Harvey, Scott Glabe and George Pappas — traveled with him, per the records. U.S. government funds paid for the group’s four-day trip, which cost just over $63,000,” the Beast reported. “The travel came as Nunes, in his role on the House Intelligence Committee, was working to investigate the origins of special counsel Robert Mueller’s probe into Russian election meddling.”

Just Security, a nonpartisan, security-focused news outlet from New York University, put together an oh-so-helpful timeline stitching together the allegations about Nunes with information developed in the course of the impeachment investigation about efforts by Parnas, Giuliani and others to discredit Biden, oust then-U.S. Ambassador to Ukraine Marie Yovanovitch, and other skulduggery by pro-Trump forces.

It all looks bad for Nunes, who has threatened to bring federal criminal charges against the Daily Beast and CNN for advancing what he called a “fake news story.” Yet there are still reasons to look twice before leaping to judgment here.

For starters, the stories were built on comments not by Parnas, but by lawyers representing him in his criminal case. And though the Daily Beast and CNN each used a different lawyer, both pieces are based on hearsay — one of Nunes’ favorite words! Even assuming the lawyers are accurately representing what Parnas told them, Parnas was relaying not his own words, but Shokin’s.

More important, though, Democrats have rejected the Parnas- and Shokin-fueled narratives about Biden and Yovanovitch as debunked conspiracy theories and smear campaigns. It’s hard to characterize someone as an opportunistic liar in one venue, then turn around and portray him a clarion of truth in another. Do they really want to rehabilitate Parnas and Shokin as witnesses for the sake of roasting Nunes?

Granted, there’s plenty of precedent for that (see, e.g., Rick Gates). And the ethics complaint filed by the Democratic Coalition makes an intriguing argument that Nunes’ interviews with key Ukrainian figures like Shokin make him a potential fact witness in the impeachment inquiry, something that not only should have been disclosed, but also should have rendered him ineligible to serve on that inquiry.

Still, I’m not ready to believe anything Parnas or Shokin says about ... anybody. Parnas in particular has an incentive to entice House Democrats to grant him immunity to testify. Such a grant could conceivably damage federal prosecutors’ ability to convict him on the campaign donations charges.

The lesson for Nunes is clear, though. It’s the same one taught by the cliche about what happens when you lie down with dogs.