Just seconds after Donald Trump appeared at his new hotel in Washington on Friday, it dawned on many of the reporters in the room and others watching the live coverage on every cable news channel that they had been conned.

Trump’s campaign had led the national press corps to expect a major announcement, in which he would retract his support for the racist conspiracy theory he has promoted for years, that Barack Obama was not born in the United States, making his presidency illegitimate. That expectation led to wall-to-wall coverage even of Trump’s plane arriving in Washington on Friday.

Instead, Trump promoted the opening of his hotel and then handed over the platform to a stream of retired military officers to praise him in glowing, and incorrect, terms.

One after the other, reporters for major American news organizations complained on Twitter that Trump had gamed the media, ensuring live coverage of an event that, for at least 20 minutes of speeches by military men singing his praises, looked and sounded like a do-over convention he had staged for himself.

But even as the press corps quietly rebelled — venting their spleen on Twitter for their followers to read — the cable networks continued to broadcast the infomercial for Trump and his hotel live to the nation.

Reporters knew they were being had, and said so on social networks, but the event continued to stream live on the airwaves in real time, with the carping confined to the safe space of social networks. The press corps stayed in their seats, or glued to their screens, waiting for the big reveal of Trump’s new position on the long-settled question of where President Obama was born.

When he finally returned, in the closing seconds of the event, Trump used the free air time to lie directly to the American people. “Hillary Clinton, and her campaign of 2008, started the birther controversy,” he said, falsely. “I finished it. I finished it, you know what I mean.”

There are two big lies here. First, Clinton and her campaign aides did not start or endorse the anti-Obama smear — it evolved from an earlier false claim, that he was secretly Muslim, first spread by an anti-Semitic Republican crank along the chain email network that gave birth to the alt right, as Chris Hayes reported in 2007. (Adherents of that claim soon demanded to see Obama’s birth certificate, and then, when it was duly produced, moved on to claiming it was fake.)*

Reporters who covered Clinton’s 2008 campaign have attested to the fact that neither the candidate nor her staff ever raised doubts about Obama’s birthplace, even as the myth that they did has become an article of faith in the right-wing blogosphere.

Second, Trump did not end the controversy, he fueled it by repeating the theory frequently, and then falsely claimed to have dispatched investigators to find evidence that the short-form birth certificate Obama released in 2008 was a forgery.

As BuzzFeed has documented, Trump has, in fact, continued to cast doubts on Obama’s birthplace over the past five years, since the president’s long-form birth certificate was released in 2011.

John Harwood of CNBC pointed out that even after he launched his campaign last year, Trump refused to stop pushing the wild claim.

At the end of the event, as political bloggers heaped scorn on their colleagues for playing along, the press corps in the hotel were left to shout helplessly for Trump to actually take questions at what was sold as a news conference.

After Trump left the room, the ABC News producer Candace Smith, who was designated to follow him on his tour of the new hotel on behalf of her colleagues in the press pool, reported that she was physically restrained from accompanying her camera operator.

That led to a decision to delete footage of Trump giving his hotel the kind of inspection viewers of North Korean state television would find familiar.

Sadly, none of that was stated in the first post-event “fact-checks” provided to cable news viewers on MSNBC and CNN, the two networks that are not pro-Trump. Hosts on both of those channels immediately responded to Trump’s naked lie by saying that it was true that some of Clinton’s supporters in 2008 had suggested Obama was not a natural-born citizen. That, of course, did not make what Trump had just proclaimed to their viewers in any sense true.

A few minutes later, CNN did bring in Jake Tapper to make it clear that no one in Clinton’s campaign had raised Obama’s birth certificate in 2008.

As the Washington Post reporter Dave Weigel noted, Clinton’s former campaign manager, Mark Penn, did suggest in a strategy memo in 2007 that one line of attack against Obama might be to argue that his upbringing in Indonesia suggested that “his roots to basic American values and culture are at best limited.”

The thrust of that internal memo, though, was not to cast doubt on Obama’s birthright citizenship, but to suggest that he might not be as electable as Clinton in 2008. Penn’s case was rooted in the idea that a candidate with such a “diverse, multicultural” background could not be elected to the American presidency for decades to come. “Save it for 2050,” Penn wrote.

When the networks got around to hearing from some of the reporters in the room who objected to the con in real time, the issue of how Trump had bent the news media to his will was finally raised.

“I think objectively the press corps got completely played,” Huffington Post’s Sam Stein told MSNBC, about an hour after Trump’s lie was beamed coast to coast.

Top photo: Reporters raised their hands in vain, waiting for Donald Trump to call on them just after he finished lying on Friday in Washington.

Correction: September 17, 2016
*An earlier version of this column incorrectly stated that the baseless rumor about Barack Obama being born overseas was started by the same anti-Semitic crank who first pushed the baseless rumor that he was secretly Muslim. While the false claim about Obama’s faith eventually led to the false claim that he was not born in the United States, the lies were not fabricated by the same person.