House Speaker Nancy Pelosi of Calif., during a news conference on Capitol Hill in Washington, Wednesday, Oct. 2, 2019. Credit: Susan Walsh | AP

President Donald Trump’s latest move to ward off impeachment may be his dumbest one yet.

On Friday, the president demanded that the full House must vote before it proceeds on an impeachment inquiry, and said he would not comply with any congressional requests for documents or testimony until it does.

He should be careful what he asks for.

The possibility for such a showdown has been in the air for days, and House Speaker Nancy Pelosi brought up the subject herself when I interviewed her Wednesday. Her reaction: Bring it.

“We can if we want but we don’t have to have it,” she said of the prospect of a floor vote to commence the investigation. “There’s nothing any place that says that we should.”

She’s right. But then the speaker brought up something that apparently hasn’t occurred to the White House: “The people who are most afraid of a vote on the floor are the Republicans. That’s why they’re beating their tom-toms like they want it but they don’t. They have the most to be concerned about because for some of their members to say that we shouldn’t go forward with this is a bad vote.”

My hunch is that Pelosi is right here. Already, there are 225 House Democrats and one independent on record in favor of moving forward with the inquiry. They have nothing to lose by backing up their words with a vote, and the resolution would pass easily. That leaves only 10 remaining Democrats facing a potentially difficult choice of whether to join the overwhelming majority in their party.

Consider, on the other hand, the spot in which this puts Republicans. As evidence of impropriety mounts each day, and public support for the inquiry grows, do they really want to cast a vote that says, “Nothing to see here”?

And once the resolution passes, what happens then? Trump’s bluff will have been called. To resist handing over necessary materials at that point only bolsters a case for obstruction of justice, which is an impeachable offense.

By forcing the House to play its hand, Trump may find out that he’s the one who is holding the losing cards.

Karen Tumulty is a Washington Post columnist covering national politics.