Acting U.S. Ambassador to Ukraine Bill Taylor testified Wednesday during the first public House hearing on impeachment that a member of his staff overheard a phone call in which President Donald Trump personally demanded information about "the investigations" he pressured Ukraine's leader to launch.

Trump's conversation with U.S. Ambassador to the European Union Gordon Sondland, according to Taylor, took place on July 26, the day after Trump urged Ukrainian President Volodymyr Zelensky to launch a probe into former Vice President Joe Biden and his son Hunter.

"The big picture here is that what separates big, historic scandals from minor ones is the personal involvement of the president."

—Paul Waldman, Washington Post

The Ukraine ambassador's account of the phone call between Sondland and Trump, which was not previously known to the public, was described as a "bombshell" that ties Trump directly to the efforts to investigate Biden.

"In the presence of my staff at a restaurant, Ambassador Sondland called President Trump and told him of his meetings in Kyiv," Taylor said during his opening remarks (pdf). "The member of my staff could hear President Trump on the phone, asking Ambassador Sondland about 'the investigations.' Ambassador Sondland told President Trump that the Ukrainians were ready to move forward."

Taylor said his staffer asked Sondland after the call "what President Trump thought about Ukraine."

"Ambassador Sondland responded that President Trump cares more about the investigations of Biden, which [Trump's personal attorney Rudy] Giuliani was pressing for," Taylor said.

Watch:

Here’s Taylor describing the new restaurant phone call between Trump and Sondland, with Sondland saying Trump specifically cares about the investigation of Biden: pic.twitter.com/LvQsMPlvHt — Casey Michel (@cjcmichel) November 13, 2019

"Ambassador Taylor's testimony leaves no doubt that President Trump was using official acts to pressure Ukraine for interference on our elections," tweeted Rep. Ted Lieu (D-Calif.) in response to Taylor's account of the July 26 phone call.

In an op-ed Wednesday, the Washington Post's Paul Waldman wrote that Taylor's testimony paints Trump "not as a disconnected figure, not as someone unaware of what is being done on his behalf, but as someone so intimately involved that he's taking phone calls from Sondland to discuss the nuts and bolts of the whole plot."

"The big picture here is that what separates big, historic scandals from minor ones is the personal involvement of the president," noted Waldman. "It's what puts Watergate, Iran-contra and the Lewinsky scandal in one category, and every other mini-scandal in another."

Impeachment HQ, a joint project of progressive groups Stand Up America and Defend the Republic, said in an email to supporters that Taylor's "testimony is absolutely devastating for Donald Trump and the Republicans attempting to defend him."

Amb. Taylor just confirmed it. We know Trump used military aid to bribe Ukraine to interfere in 2020. We know anyone else who did that would be in jail. What we don’t know is if there’s a single Republican in Congress who will uphold their oath to defend our Constitution. pic.twitter.com/Xf77JX7VwQ — Stand Up America (@StandUpAmerica) November 13, 2019

At least one Republican operative was reportedly alarmed by the first day of public impeachment hearings, during which House Republicans and GOP counsel Steve Castor peddled right-wing conspiracy theories in defense of Trump.

"Not from me: but this is a massive fucking shitshow," an unnamed GOP operative told Bloomberg reporter Sahil Kapur. "No one wants to be here."