President Trump tweeted on June 22 that he doesn't possess — and didn't record — tapes of his private conversations with former FBI director James B. Comey. (Peter Stevenson/The Washington Post)

This post has been updated with Trump's tweets.

President Trump acknowledged Thursday that he doesn't have any tapes of conversations with former FBI director James B. Comey, finally coming clean after playing a nearly six-week-long game.

And in the end, it wasn't just another bluff from Trump; it was another bluff that was called and that continued to chip away at Trump's honesty and credibility, for no discernible benefit.

The president last month wielded those potential tapes as a very thinly veiled threat against Comey. And ever since then, Trump and the White House have decided to withhold the truth from the American people, refusing to answer a simple yes-or-no question about whether they had tapes.

But Newt Gingrich just gave away the game earlier Thursday, for all intents and purposes. In an interview with the Associated Press, the Trump-backing former House speaker basically admitted that Trump was bluffing to try to get inside Comey's head.

“I think he was, in his way, instinctively trying to rattle Comey,” Gingrich said. “He's not a professional politician. He doesn't come back and think about Nixon and Watergate. His instinct is: 'I'll outbluff you.' ”

Apparently not being a “professional politician” is a license for dishonesty — because that's what this was.

This is just the latest in a long line of Trump bluffs. There was the time he was going to force the House to vote on its health-care bill, pass or fail, until he urged that it be delayed in the face of defeat. There was the time during the spending debate when the White House signaled that Trump would allow a shutdown if the bill didn't fund his border wall, only to back down a couple of days later. More examples abound.

But this has been a particularly brazen brand of bluffing from the president of the United States. Trump threatened a former top government official using a falsehood to try to get him to soften his testimony. It's not difficult to attach this to the lengthening list of things suggesting that Trump has tampered in the Russia investigation or even obstructed justice in doing so.

And for a president who has huge trouble with facts, it displays a striking disregard for the truth. No, Trump never said clearly that he had the tapes, but he has left that possibility out there for weeks, refusing to go on the record. Politics tends to be a rough-and-tumble business, but this is pretty unapologetic political nihilism, plain and simple.

It also has shelf life. I argued after one of Trump's previous bluffs that this kind of strategy may pay dividends in the business world and in the near term as president, but that as a politician it can and will catch up to you:

This kind of bluffing and having it called is undoubtedly something Trump is used to in the business and real estate worlds. But in the political world, you are negotiating with the same people over and over again. And the lesson of the first two big congressional debates is that when Trump says a bill must contain XYZ, he doesn't really mean it; it's just posturing. And that doesn't bode well for future Trump demands.

During the last government shutdown in 2013, when Republicans demanded defunding Obamacare, they were at least willing to follow through on that demand. The government was closed for more than two weeks before the GOP relented. That served notice to Democrats that Republicans were at the very least willing to go all-in on their strategy and follow through — that they weren't bluffing when they made such demands in order for a bill to pass. And that made their threats on other things seem more legitimate.

Trump has shown no such inclination to make it so people take his demands at face value. And given what's happened in the first two legislative debates, the next time he draws a line in the sand, you can bet lawmakers know how easily it can be raked over.

And the final point here is that Comey essentially called Trump's bluff. In blistering testimony that pointed to Trump's potential obstruction of justice two weeks ago, Comey didn't hold back at all. And at one point, he addressed the threat of tapes directly and suggested they would vindicate him if they did exist.

Former FBI director James B. Comey said he has seen President Trump's May 12 tweet that suggested there could be "tapes" of their private conversations, saying "Lordy, I hope there are tapes." (Reuters)

“I’ve seen the tweet about tapes,” Comey said. “Lordy, I hope there are tapes.”

So Trump appears to have not only done something dishonest that undermines his credibility going forward, but it didn't even work. At least the charade is over.