WASHINGTON — In Washington, you can usually measure the weight of an event by the density of the cameras that surround the witness stand.

On Wednesday, the TV shooters and still photographers ran about three dozen deep, massing like a firing squad in front of a long, low table with four seats and two white placards: “AMBASSADOR TAYLOR” and “MR. KENT.”

It was the setting for an extraordinary hearing and a historic day in the Capitol, even by the standards of the three years of President Donald Trump’s administration. Beneath tall blue curtains, grim-faced Democrats and Republicans opened public testimony into what is likely to become the third presidential impeachment in American history.

When the hearing began, the icy-cold room fell silent save for a faint electronic hum.

“With that, I give my opening statement of the impeachment inquiry into Donald J. Trump, the 45th president of the United States," said Rep. Adam Schiff (D., Calif.), chairman of the House Intelligence Committee.

For weeks, the words of William Taylor, the top U.S. diplomat in Ukraine, and George P. Kent, a deputy assistant secretary in the State Department, have pinged through news reports about their private depositions to lawmakers, but Wednesday marked the first time most of America would see their faces and hear their voices.

Rep. Jim Jordan (R., Ohio) derisively pegged Taylor as the Democrats’ star witness. It was a label Taylor, a West Point graduate, Vietnam veteran, and decades-long foreign service officer, tried to shed. “I don’t consider myself a star witness or anything.... I’m not here to take one side or the other or to advocate any particular outcome.”

The bowtied Kent, in his opening statement, said he had “proudly served as a nonpartisan career Foreign Service officer for more than 27 years under five presidents: three Republicans and two Democrats.”

Yet the hearing marked another moment when people who have spent their lives behind the scenes become major players in a national drama.

More than 100 journalists were credentialed to attend Wednesday’s hearing. Three rows of tan leather chairs were reserved for House members who don’t sit on the Intelligence panel, which convened the first public hearing in the impeachment inquiry.

A few dozen members of the public ambitious enough to get in line at 7 a.m. were ushered into the room shortly before the witnesses arrived. Some carried folding camp chairs.

Taylor and Kent walked in at 10:04 a.m., smiling thinly as cameras whirred and clicked. After a few minutes, House staff urged the photographers back, like game wardens herding animals to a pen. “On your butts, guys! On your butts!”

In Taylor, who has served in foreign affairs roles under every president from Ronald Reagan to Trump, Democrats hoped they had a witness who could win the public’s trust and deliver a clear account of what the president did, and why it mattered to Ukraine and U.S. national security interests.

Speaking in deep, resonant tones that could narrate pickup-truck commercials, Taylor meticulously laid out the details of how he came to understand that Trump and his allies had stalled vital military aid to Ukraine unless the country agreed to investigate a political rival, Joe Biden, and a debunked conspiracy theory about Ukrainian 2016 election interference on behalf of Democrats.

Taylor said aid to Ukraine was not only important to help an ally and promote democracy, but was in America’s national security interest. Aiding Ukraine, he said, bolsters a country facing Russian aggression that is on the front lines of keeping that rival in check.

He also dropped a potentially significant new piece of information, saying he had recently learned from an aide that Trump had personally asked European Union Ambassador Gordon Sondland about the requested investigations. Sondland, according to Taylor’s account, told the aide that Trump “cares more about the investigations of Biden" than corruption in Ukraine.

The stakes for Trump were illustrated by Jordan’s presence. One of the president’s most dogged and fierce defenders was added to the Intelligence Committee specifically to respond to this investigation. As the hearing began, Jordan, a former wrestling coach, rocked back and forth in his chair, like a boxer bouncing on his toes before the bell. As is his signature, he was the only lawmaker without a jacket.

Unlike most congressional hearings, the opening questions were handled by staff attorneys who each got a 45-minute bloc to probe, follow up, and develop clear answers. The focused inquiries contrasted with the typical five-minute question periods, mostly consumed by lawmakers’ grandstanding and veering from one line of questioning to the next.

Later, when lawmakers got their turns, Rep. John Ratcliffe (R., Texas), a former trial lawyer, spent most of his five minutes laying out an argument, then asked Taylor for a “yes or no” response because “my time is short.”

Despite the potential consequences, however, after a while the atmosphere resembled many more routine hearings, except with more media and security. Lawmakers in the audience scrolled on their phones or tapped on laptops for much of it.

And outside of the committee members on the dais, most of the seats reserved for Congress remained vacant.

Closed-door depositions by multiple Trump administration officials had already painted a picture of Trump pressuring Ukraine using hundreds of millions of dollars of congressionally appropriated military aid as leverage. Democrats point to the actions as clear evidence of an abuse of power.

Trump has said his call with Ukraine’s president was “perfect” and Republicans have argued that his behavior was within his rights as president, at worst inappropriate but not impeachable. They accuse Democrats of trying to overturn the 2016 election.

Democrats hope public hearings, after a vote to formally authorize the impeachment inquiry in October, will move public opinion in a way that July hearings with special counsel Robert Mueller did not. While Mueller’s taciturn performance sucked the air out of his findings on Russian interference in 2016 and Trump’s potential obstruction of his investigation, the two witnesses Wednesday were chosen to breathe life into their private testimony on Ukraine, and lay out the stakes.

“I want to look at this with my own eyes, as 300-something million Americans will be,” said freshman Rep. Dean Phillips (D., Minn.), one of the lawmakers who is not on the Intelligence Committee but chose to attend. “That’s why I think being in the room is important.” He later added, “it’s our darn responsibility.”

The hearing was aired on network and cable TV, and dissected blow-by-blow on Twitter.

Yet much of the hearing served as a reminder of the competing news bubbles that now encapsulate so many Americans.

While Democrats focused on the testimony of the career diplomats in front of them, Republicans dug for anything that might support some of the president’s favorite obsessions, familiar to consumers of conservative media, including that Biden tried to protect his son, Hunter, who served on the board of a Ukrainian energy company with a questionable history.

Kent, who had raised concerns of an ethical conflict, flatly said there is no evidence “whatsoever” Joe Biden acted out of self-interest, and that he was carrying out U.S. policy as vice president.

After more than five hours, the hearing ended, and Taylor and Kent left through tall double doors. Another squadron of cameras awaited as they exited the building.

Taylor walked quickly but calmly, ignoring shouted questions from a few journalists. The ex-Army man had fulfilled what he clearly saw as another obligation of public service, but was in no mood to linger.