This post has been updated to note Trump promoting the tweet.

Republicans have repeatedly argued that the impeachment evidence against President Trump is thin. They’ve said it is based upon “hearsay” that wasn’t corroborated by people more intimately involved with the Ukraine effort (whose testimony the White House has blocked). They’ve suggested, despite numerous witnesses testifying to similar things, that the witnesses weren’t credible and that they might have axes to grind.

But on Thursday, with House Democrats playing video of those witnesses’ testimonies during Trump’s impeachment trial, a Republican senator launched her own thinly sourced attack on one of those witnesses.

And then Trump retweeted it.

Sen. Marsha Blackburn (R-Tenn.), who along with every other senator serves as a juror in the impeachment trial, took to Twitter and impugned the patriotism of Lt. Col. Alexander Vindman.

Blackburn referred to an allegation that Vindman had badmouthed the United States in a conversation with Russians while serving overseas.

“Adam Schiff is hailing Alexander Vindman as an American patriot,” Blackburn said. “How patriotic is it to badmouth and ridicule our great nation in front of Russia, America’s greatest enemy?”

Trump then retweeted the allegation Friday morning.

The problem with this very severe allegation — made against a Purple Heart recipient who served in Iraq, no less — is that it’s anything but verified. It was made on Twitter in November by someone who said they had served with Vindman. Another person later launched a Twitter account confirming it. The New York Times reported that the originator of the claim had also trafficked in QAnon conspiracy theories but claimed they didn’t necessarily believe in the movement.

A retired general, Mark Hertling, said at the time that he had spoken to the individuals who accused Vindman and confirmed their backgrounds. But Hertling told the Times that he felt there were holes in their story — including the idea that Vindman, a fluent Russian speaker born in the Soviet Union, would have been conversing with Russians in English.

Lt. Col. Alexander Vindman told a House investigative committee that despite putting himself in direct opposition to President Trump, in America “right matters" (The Washington Post)

Vindman’s lawyer on Thursday called Blackburn’s allegations “defamatory.”

“That a member of the Senate — at a moment when the Senate is undertaking its most solemn responsibility — would choose to take to Twitter to spread slander about a member of the military is a testament to cowardice,” said the lawyer, former ambassador David Pressman. “While Senator Blackburn fires off defamatory tweets, Lieutenant Colonel Vindman will continue to do what he has always done: serve our country dutifully and with honor.”

Even as Blackburn took criticism Thursday for her tweet, she doubled down. She quoted Vindman’s initial accuser and also accused Vindman of being a source for the whistleblower who launched the Ukraine scandal. Vindman said in his testimony that he spoke with an intelligence community official about Trump’s July 25 call with Ukrainian President Volodymyr Zelensky, which he was on, but he declined to identify the official, on advice of counsel because he said he didn’t want to identify members of the intelligence community. There is no public evidence that he was a whistleblower’s source.

Blackburn, though, stated it as fact, without providing evidence.

In doing so, Blackburn re-upped an unfounded claim she made previously that Vindman was the whistleblower’s “handler.” To this day, that allegation — “Vindictive Vindman is the ‘whistleblower’s’ handler” — remains the pinned tweet on the senator’s account.

She sent a similar tweet Thursday night, quoting Vindman’s initial accuser, and this one was later retweeted by President Trump himself.

At the time of Blackburn’s original “Vindictive Vindman” tweet, Republicans in the House’s impeachment inquiry and elsewhere offered plenty of innuendo about Vindman, including suggesting he might have more loyalty to Ukraine because he was born in the Soviet Union and accusing him of inflating his importance. Blackburn took it further than most any other Republican, stating the accusation as fact. She did the same with her Thursday night tweet.

Vindman indicated in his testimony that he knew the attacks were coming, but he insisted that telling the truth was important. He addressed his Soviet-born father, who he said had reservations about him testifying in ways that could earn the ire of Trump and his supporters — and might have led to worse in the Soviet Union.

Vindman told his dad that “sitting here today in the U.S. Capitol, talking to our elected professionals, is proof that you made the right decision 40 years ago to leave the Soviet Union and come here to the United States of America, in search of a better life for our family. Do not worry, I will be fine for telling the truth.”

On Thursday, a U.S. senator yet again offered her own flimsy version of the truth about him.