Vindman’s testimony sidesteps the whistle-blower complaint that kicked off this scandal. Unlike the whistle-blower, whose identity is still unknown, Vindman had firsthand knowledge of the call; he also complained up the chain of command.

Vindman would seem like a difficult witness to attack: a career soldier, an active-duty lieutenant colonel in the Army, a Purple Heart recipient for a wound from an IED in Iraq. Yet imagining that Trump’s allies might struggle to impugn Vindman badly overestimates their scruples.

Shortly after the statement was released, Laura Ingraham covered his story on her Fox News show.

“This is buried in the New York Times piece tonight,” Ingraham said. “He’s a decorated colonel, by the way, in the Iraq War. ‘Because [Colonel Vindman] emigrated from Ukraine along with his family when he was a child and is fluent in Ukrainian and Russian, Ukrainian officials sought advice from him on how to deal with Mr. Giuliani, though they typically communicated in English.’”

She went on: “Here we have a U.S. national-security official who is advising Ukraine while working inside the White House, apparently against the president’s interest, and usually they spoke in English. Isn’t that kind of an interesting angle to this story?”

David A. Graham: Impeachment just became inevitable

Ingraham’s comment is spurious in several ways. First, it was Vindman’s job to speak with Ukrainians. Second, it is of course useful for foreign-policy professionals to speak the language of the foreign countries they handle. Third, other officials, including Sondland and Ambassador William Taylor, have recounted offering advice to Ukrainians about navigating their relationship with Rudy Giuliani. Fourth, there is no evidence that Vindman was acting against the president’s interest; indeed, he was trying to execute official U.S. foreign policy regarding Ukraine, even as Giuliani ran a rogue and dubiously legal shadow foreign policy.

John Yoo, a former official in George W. Bush’s administration and a law professor at UC Berkeley, reacted to Ingraham’s prompt by casually accusing Vindman of treason.

“I find that astounding, and some people might call that espionage,” Yoo said. (This may illustrate the danger of allowing Yoo, the author of a Bush-era legal opinion justifying torture, to weigh in on questions of law and morality.) Later on Tuesday, responding to a torrent of criticism, Yoo told the Washington Examiner that he “meant to say that this sounded like an espionage operation by the Ukrainians.”

The attacks continued Tuesday morning. On CNN, the newly hired contributor and former Representative Sean Duffy baselessly accused Vindman of dual loyalty or treason.

“It seems very clear that he is incredibly concerned about Ukrainian defense,” Duffy said. “I don’t know that he’s concerned about American policy, but his main mission was to make sure that the Ukraine got those weapons. I understand that. We all have an affinity to our homeland, where we came from … He’s entitled to his opinion. He has an affinity for the Ukraine, he speaks Ukrainian, and he came from the country, and he wants to make sure they’re safe and free. I understand that.”