Then-White House counsel Donald McGahn in the Roosevelt Room of the White House on May 24, 2018. (Jabin Botsford/The Washington Post)
Opinion writer

President Trump claimed in his ABC News interview that former White House counsel Donald McGahn lied about Trump’s instructions to fire special counsel Robert S. Mueller III:

“The story on that very simply, No. 1, I was never going to fire Mueller. I never suggested firing Mueller,” Trump told [George] Stephanopoulos.

But when Stephanopoulos pushed back and referenced McGahn's testimony, Trump was defiant.

"I don't care what [McGahn] says, it doesn't matter," Trump said.

“Why would [McGahn] lie under oath?” Stephanopoulos later asked.

“Because he wanted to make himself look like a good lawyer,” Trump said. “Or he believed it because I would constantly tell anybody that would listen — including you, including the media — that Robert Mueller was conflicted. Robert Mueller had a total conflict of interest.”

“And has to go?” Stephanopoulos followed up.

“I didn’t say that,” Trump insisted.

Trump naturally assumes McGahn would lie to protect his reputation because this is what Trump does over and over again. Stephanopoulos’s brilliant follow up (“And has to go?”) should convince all but the most Trump-intoxicated cult members that there is no way in the world Trump would have academically opined on Mueller’s conflicts without telling McGahn to do something about it.

Moreover, Trump quickly falls back to his “obstruction doesn’t matter” reasoning: “Just so you understand. Very simple. It’s very simple. There was no crime. There was no collusion. The big thing’s collusion. Now, there’s no collusion. That means they set — it was a setup, in my opinion, and I think it’s going to come out.” Actually, the big thing is the president violated his oath to enforce the law by engaging in a widespread pattern of obstruction. That is a crime. Period.

McGahn very likely will be compelled to testify when House Democrats take his contempt citation to court. The necessity of his testimony is even more evident after Trump’s flat denial. Americans can judge for themselves whether the notoriously dishonest president is telling the truth or whether McGahn, who spent 30 hours with Mueller and apparently took notes during his conversations with Trump, is trying to set up his former boss.

Oh yes, the notes. According to McGahn, Trump berated him for keeping notes. ("What about these notes? Why do you take notes? Lawyers don’t take notes. I never had a lawyer who took notes.”) Mueller almost certainly obtained those notes. Now that the House Judiciary Committee is reviewing the underlying evidence on which Mueller based his report, the House will get those as well. There may also be other direct witnesses to these conversations or other witnesses whom McGahn contemporaneously spoke to about Trump’s orders.

In short, this is unlikely to be a case of “he said-he said." Rather, it will be “he said-he said ... and the notes said, and other witnesses said.” Trump has this notion that if he impugns a witness (e.g., McGahn, Michael Cohen) he will emerge triumphant or at least so muddy the waters that his lackeys in Fox News and other right-wing media will find excuses to stick with him.

The problem, however, is that a skilled prosecutor such as Mueller never relies on one witness; it would be shocking if Mueller didn’t have separate confirmation of McGahn’s account. And while Trump can bank on 35 percent of the electorate to ignore all evidence of his guilt, the rest of the electorate — and future prosecutors — will be unmoved. Indeed, the lies on top of lies serve to confirm his willingness to obstruct an investigation into his own wrongdoing.

It’s critical that Congress and the public hear directly from McGahn and see the underlying evidence. Republicans will have to defend Trump despite all that, confirming their role as Trump enablers. As Trump digs himself into a seemingly bottomless sinkhole of lies, he takes his party down with him. That’s a fitting end to those without whose indulgence Trump could not remain in office.

Read more:

Greg Sargent: Trump camp’s latest lies cannot obscure what’s now been exposed

Dana Milbank: This is worse than Watergate

Harry Litman: Trump’s legal case for executive privilege is strained at best

Max Boot: Trump has bragged that he will break the law

Greg Sargent: Why is Trump raging again? Because Don McGahn will further expose his corruption.