The impeachment surprise on Day 1

In a surprise revelation during a day with more drama than news, the top U.S. diplomat to Ukraine testified during the House impeachment hearing that he learned about another Trump phone call last week.

Driving the news: Bill Taylor learned last week that a staffer overheard President Trump discuss "the investigations" in Ukraine with EU Ambassador Gordon Sondland the day after Trump's July 25 call with the president of Ukraine, he told the House Intel Committee today.

Why it matters: It’s an example of Trump personally involving himself at the ground level with the push to have the Ukrainian president announce these investigations.

• It would tie Trump more directly to the pressure campaign and make it more difficult to say it was Rudy Giuliani going rogue, or just Sondland’s interpretation of what Trump wanted.
• Trump responded at a presser: "I know nothing about that. First time I've heard." (Video).

The big picture: No one's expecting to learn much from these hearings, which feature witnesses who've already been deposed behind closed doors.

• Democrats hope the public will be galvanized by a stream of public servants speaking out about abnormal behavior.
• Republicans hope they can keep the discussion focused on improprieties by people who aren't named Donald J. Trump, including even alleging wrongdoings by prior administrations.

Between the lines: Taylor and George Kent said they had never had contact with the president.

• Reality check: The White House is blocking most of the people who've had contact with Trump from testifying.
• Instead, Taylor and Kent emphasized, their presence was to answer questions and express their alarm at the abnormality of the actions they witnessed from their own government this year in Ukraine.

What they're saying: House Democratic aides think this went better than Robert Mueller's hearing, but are worried that no matter what happens in these hearings, viewers will continue to see this through a partisan lens, Axios' Alayna Treene reports.

• "The contrast of Taylor to Mueller ... is jarring. ... Taylor is in full command," the N.Y. Times' Maggie Haberman wrote on the Times live blog.

The bottom line: History is unfolding before us, but due to the splintering of modern media, expect people to walk away with very different impressions of what they're seeing — depending on where they see it.

Go deeper: More highlights from today's testimonies