This post has been updated.

President Trump is no stranger to bluffing, but rarely has he had his bluff called so hard and fast as he did by House Speaker Nancy Pelosi (D-Calif.) on Wednesday.

Trump sent a letter early in the afternoon declaring he would show up to deliver his State of the Union address in the House chamber next week, regardless of Pelosi’s shutdown-related objections. “I will be honoring your invitation, and fulfilling my Constitutional duty, to deliver important information to the people and Congress of the United States of America regarding the State of our Union,” Trump wrote. “I look forward to seeing you on the evening on January 29th in the Chamber of the House of Representatives.”

It was unambiguous: Trump said he was coming, and he was challenging Pelosi to stop him.

So she stopped him. And he backed down almost immediately.

Shortly after Trump sent his letter, Pelosi wrote back saying she would not allow him to speak from the House chamber until the shutdown is over. “I am writing to inform you that the House of Representatives will not consider a concurrent resolution authorizing the President’s State of the Union address in the House Chamber until government has opened.”

Shortly after that, Trump conceded the whole charade, saying he would use an “alternative" method of delivering his address and that it wouldn’t be in the Capitol. Basically: He admitted he wasn’t going to follow through on the threat he’d made just a couple hours earlier.

“The State of the Union has been cancelled by Nancy Pelosi, because she doesn’t want to hear the truth," he said.

The dueling letters set the stage for a potentially high-profile and fraught standoff. It put Trump in the position of making good on a very big promise if Pelosi wouldn’t budge. Was he really going to show up to try to deliver a speech he hadn’t been invited to give, we all wondered, and risk being turned away?

As my colleague Colby Itkowitz summed it up: Legally speaking, Trump has no right to deliver the speech in the House chamber. The Constitution says only that a president must provide an update on the state of the country. This used to be done in writing (an option Pelosi helpfully suggested in her letter to Trump last week). Congress can provide the chamber and has for more than 100 years, but it must be done through a joint resolution. Pelosi earlier this month invited Trump to deliver the speech, but such a resolution has been neither taken up nor passed.

It’s worth noting that Pelosi hadn’t technically uninvited Trump yet. In her letter last week, she merely suggested a postponement (or a written version) because of security concerns related to the shutdown. But Trump essentially dared her to follow through, and she did.

Which shouldn’t have come as a surprise. Ever since Democrats won back the House in November, Pelosi has shown she won’t exactly back down from a fight. In fact, this is a fight she started. And with Democrats in control of the shutdown battle, it was tough to see why she would do that, unless they reached some kind of compromise for the purpose of de-escalating the whole thing.

But Trump tried it anyway. And he probably gave himself no choice but to back down. If you were him, do you show up to deliver the speech and risk being turned away by the House sergeant-at-arms? To do so would be to run afoul of the law. And even if it worked, it would mean delivering a speech to a chamber that might be empty or include no Democrats. Pelosi also controls the cameras and audio.

In the end, Trump placed a bet on a strategy that seemed unlikely to bear fruit unless Pelosi shocked everyone by reversing course. But the gamble was always liable to backfire.

Everyone is looking for a sign of weakness in the other side’s shutdown resolve. On Wednesday, Trump tried to find Pelosi’s; instead, he outed himself as a bluffer.