If the opening of the House impeachment hearings accomplished one thing, it was allowing the public to judge the credibility of two veteran diplomats who have been under attack as rogue NeverTrumpers.

This was, after all, the first opportunity virtually all Americans to hear William Taylor and George Kent speak.

As career officials, they brought a measured, no-nonsense style that was surprisingly effective. They were fairly unflappable yesterday under questioning by a Republican counsel who minimized their complaints and tried to shift the focus to Hunter Biden’s money-making role in Ukraine, about which the witnesses had no first-hand knowledge.

In effect, the GOP wisely chose not to directly challenge their credibility while attempting to portray what happened with President Trump and Ukraine as nothing out of the ordinary.

The first half, at least, was less theatrical than most congressional hearings because nearly all the questioning was conducted by each side’s lawyer. This greatly limited the role of Intel chairman Adam Schiff, a ubiquitous cable news figure who many dismiss as a partisan figure.

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Kent, a State Department official, looked like a bow-tied history professor, drily describing the history of Russian aggression that has led to the deaths of more than 13,000 Ukrainians.

Taylor, who accepted the acting ambassador’s post over his wife’s objections, was more forceful in demeanor, a central-casting diplomat building a just-the-facts timeline. When he learned from an OMB official that military aid to Ukraine was being held up, “I and others sat in astonishment.” He observed an “irregular channel,” including Mick Mulvaney, Rudy Giuliani, Rick Perry and Gordon Sondland, driving Ukraine policy.

But Taylor had to own up to more colorful language when asked to read his text to Sondland, the Trump donor-turned-ambassador: “I think it’s crazy to withhold security assistance for help with a political campaign.” Asked by Democratic counsel Daniel Goldman to explain that word, Taylor said it “made no sense” and was “illogical” to withhold U.S. aid to Ukraine “for no good reason.”

He also had sent a text about a suggestion that Ukrainian president Zelensky announce the investigations that Trump wanted on CNN: “My nightmare is the Ukrainians give the interview and don’t get the security assistance.”

Taylor broke a little new ground beyond his closed-door testimony. He said Sondland told him he’d “made a mistake” in saying only a Trump-Zelensky meeting was at stake in the impasse over announcing investigations: “Everything was dependent on such an announcement.”

Taylor also testified that Sondland told a fellow diplomat, who asked what Trump thought about Ukraine, that the president "cares more about the investigations of Biden.”

Republican counsel Steve Castor spent part of his time pressing the witnesses on Ukrainian corruption and Burisma, the giant gas company, hiring the younger Biden. Then Castor made the case that the so-called irregular channel is “not as outlandish as it could be.” Taylor allowed that that was true.

GOP Rep. Jim Jordan hammered Taylor by saying he had never talked to Trump, that Zelensky never raised the frozen aid with him, and that in the end Ukraine got its American funding. Taylor said he could only testify about conversations he had and stressed that he was not there as an advocate or as anyone’s “star witness.”

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Another Republican, John Ratcliffe, tried to get Taylor to take a stand: “Where is the impeachable offense in that call?”

The congressman kept interrupting Taylor, who finally managed to say: “I’m not here to take one side or the other.”

The White House scoffed at Day 1, with Press Secretary Stephanie Grisham tweeting: “These are essentially two bureaucrats with a foreign policy gripe.” And the president told reporters: "I hear it's a joke...This is a sham and shouldn't be allowed."

The Republican defense at the hearing: Ukraine and Hunter Biden are corrupt, the witnesses have nothing directly on the president, and in the end the Ukrainians got more military aid than under Barack Obama without making promises.

The Democratic offense at the hearing: The two diplomats are describing a blatant quid pro quo, backed up by text messages, and Trump’s side can’t contradict those basic facts.

Since this debate has been raging for weeks, I’d be surprised if these hearings move the needle on public opinion at all.