Four witnesses were called to testify on the third day of public hearings into the House impeachment inquiry. Of the four, Alexander Vindman, a National Security Council staffer and a US Army lieutenant colonel, was the only witness to come in full military garb — an outfit that placed Vindman’s military career on full display.

It’s standard practice for military officers testifying on Capitol Hill, but the dress uniform became a flashpoint on Tuesday.

Vindman is the top Ukraine expert on the NSC, which advises the president on national security and foreign policy matters, and has served in American embassies in Ukraine and Russia.

As Vox reported, that makes Vindman the first White House aide to testify in the inquiry. Vindman said he has not personally interacted with President Donald Trump, but was on the line for Trump’s two phone calls with Ukrainian President Volodymyr Zelensky in April and July.

Related What we learned from the third day of public impeachment hearings

Despite his background as a decorated veteran, Vindman has been criticized by Republicans and conservatives on cable television for complying with the House subpoena to testify. On Monday, the night before Vindman’s testimony, Republican lawmakers, including Sen. Ron Johnson of Wisconsin and Rep. Doug Collins of Georgia, attacked his credibility as a witness, the Washington Post reported. Fox host Laura Ingraham and CNN commentator Sean Duffy have also questioned Vindman’s patriotism and national loyalty through insinuations about his immigrant background. (Vindman’s family fled the Soviet Union as refugees 40 years ago.)

On Tuesday, Republican attorney Steve Castor also used his time to ask Vindman about whether he was offered the post of Ukrainian defense minister. This line of questioning seems to be part of a conservative effort to discredit Vindman’s allegiance to the US.

The uniform, then, became a focus point for Republicans who believe the soldier wants to look more authoritative, and another line of attack for the GOP to question Vindman’s credibility.

Dressed in uniform, Vindman emphasized how the Army is nonpartisan. Republicans tried to paint him as un-American anyway.

Vindman, a Purple Heart recipient, previously wore his decorated Army uniform to the closed-door hearings in late October. While his outfit is more of a formality than a personal choice, the uniform could create the perception of credibility, especially among the public. Regardless, Vindman seemed intent on publicly presenting himself as an Army veteran in accordance to his testimony as a national security staffer.

From the start, Vindman sought to highlight his work as a public servant in the opening statement: “I have dedicated my entire professional life to the United States of America,” he said.

“The uniform I wear today is that of the United States Army … We do not serve any particular political party, we serve the nation. I am humbled to come before you today as one of many who serve in the most distinguished and able military in the world,” Vindman added.

The Washington Examiner, a conservative news site, reported that members of the military who serve with the NSC typically wear suits, citing various unnamed military officials who disagreed with Vindman’s outfit. There’s a case for that: active-duty troops can wear civilian business attire if given a waiver to do so. It’s unclear if Vindman was given permission to wear a suit instead of his uniform to the hearing.

Trump’s former National Security Adviser H.R. McMaster has worn his Army uniform for some official duties in the White House, according to the Military Times in 2017. McMaster’s choice of dress was “an apparent break from other senior military officers who’ve served as high-profile political appointees while remaining on active duty.”

And again, that’s in the daily business of the NSC — not in front of lawmakers on Capitol Hill.

Vindman is still an active-duty Army officer, and according to retired naval aviator Guy Snodgrass in an interview with Cheddar, “it’s [Vindman’s] obligation, in accordance with his oath of office, to [testify] in uniform.”

Because there's mixed reporting (and bad takes) about this issue, here's what retired Naval aviator Guy Snodgrass told me this last week about Lt. Col. Vindman appearing on the Hill in uniform: pic.twitter.com/Cgs0fhsF0m — j.d. durkin (@jiveDurkey) November 19, 2019

When referred to as “Mr. Vindman” during his testimony by Rep. Devin Nunes, Vindman interrupted to ask the Republican representative to use the proper title of lieutenant colonel when addressing him.

Rep. Devin Nunes refers to Lt. Col. Alexander Vindman as "Mr. Vindman."



"Ranking member, it's lieutenant colonel Vindman, please," Vindman responds. https://t.co/SfAn7B5WcJ #ImpeachmentHearings pic.twitter.com/3i5D3OlMNP — ABC News (@ABC) November 19, 2019

The uniform-based attacks were part of a broader hit on Vindman’s integrity. Republicans questioned the officer’s loyalty to the US because he speaks Ukrainian and emigrated from that country to America with his father. They targeted how Ukraine’s government thrice offered him the role of defense minister, which Vindman each time declined. And they painted him as a deep state operative looking to thwart Trump’s foreign policy.

They proved none of it. But when their defense of Trump’s conduct toward Ukraine lacks any merit, going after a witness is all they really have left.

Vindman isn’t the first NSC staffer to testify in full military uniform

Collins, the Republican lawmaker who criticized Vindman, doesn’t think that wearing a uniform would shield the NSC staffer from tough questions at the hearing, the Post reported. “I don’t think it shielded Oliver North from hard questions,” Collins told reporters.

Oliver North was a key witness in the 1987 Iran-Contra hearings, which was part of a congressional inquiry into whether President Ronald Reagan’s administration used profits from weapons sales to Iran to secretly fund a right-wing rebellious coup in Nicaragua.

Tens of millions of people across the nation tuned in to watch the Iran-Contra hearings; North, a staffer on the National Security Council and a key decision maker in the events of the scandal, was one of the most anticipated witnesses.

While testifying, North wore a green Marine Corps uniform, decorated with six rows of service ribbons and a White House staff badge.

During his testimony, North admitted that he had lied and misled Congress and the American public by falsifying official documents to protect his superiors and the president. Still, his testimony — somewhat influenced by his appearance in full military garb — resonated with the public.

A Washington Post columnist wrote that North “cleverly projected himself as a brave, America-loving Marine who put the nation’s interest above that of even his family.” And it worked: “An ABC news poll cited by The Post at the time found that 92 percent of the public thought that North did well in defending his actions; 64 percent came to see him as a victim and not a villain in the scandal.”

Arguably, the significance of North’s uniform was not the ribbons that reflected his military career and administrative achievements (his decorations were “no more distinguished than what might be seen on many lieutenant colonels’ chests,” the Sun Sentinel reported in 1987). It was the White House badge he wore despite being fired from his NSC post by Reagan as the scandal publicly unfolded.

The Los Angeles Times reported, “Once that badge was reserved for military officers actually serving on the President’s staff. But a recent rule change allows former White House staff officers, like North, to continue wearing the badge — even though his actions helped plunge President Reagan into the worst crisis of his presidency.”

North’s testimony in full military uniform swayed public opinion in his favor, despite his direct involvement in the Iran-Contra scandal. Vindman — a witness on Trump’s call to Ukraine who has no established connection with the President — has faced attacks on his credibility and patriotism, on top of his decision to wear a military uniform.

To his detractors, it’s a disgraceful choice to don a military outfit while testifying against the expected chain of command. To his supporters, it’s a symbol of Vindman’s patriotism and duty to his country beyond partisan politics.