Even as President Trump's falsehoods go, this one was pretty blatant: Two months after he unsuccessfully tried to fire Robert S. Mueller III, Trump denied that he had even considered doing such a thing.

I haven’t given it any thought,” Trump told reporters in Bedminster, N.J., in August. “Well, I’ve been reading about it from you people. You say, ‘Oh, I’m going to dismiss him.’ No, I’m not dismissing anybody.”

Trump's presidency has quite often inhabited the darker side of the gray area between truth and lies. But here he was talking about a huge, consequential moment in the Russia investigation — one in which he clearly participated — and said something that has now been reportedly proved false. “Lie” is a word that journalists still shy away from with Trump, given it requires knowing Trump's intent and what he was aware of at the time. But this is as close as it comes to a provable one.

But does that matter to Mueller?

The impeachment of President Bill Clinton in the 1990s focused on his having lied under oath, but the last of the 11 grounds for impeachment in special counsel Kenneth Starr's report dealt with a different kind of lie: One told to the American people. Clinton's most infamous lie — his finger-wagging “I did not have sexual relations with that woman, Miss Lewinsky” — was delivered to cameras rather than investigators. Starr listed it and other false public denials under Ground XI, in which Starr alleged that Clinton's actions “have been inconsistent with the President's constitutional duty to faithfully execute the laws.”

As Starr described it:

By publicly and emphatically stating in January 1998 that “I did not have sexual relations with that woman” and these “allegations are false,” the President also effectively delayed a possible congressional inquiry, and then he further delayed it by asserting Executive Privilege and refusing to testify for six months during the Independent Counsel investigation. This represents substantial and credible information that may constitute grounds for an impeachment.

The argument was basically that Clinton's lies to the American people hindered the legal process — that he obstructed justice. So could Trump's false statement about not even considering firing Mueller hurt him in a similar way, if Mueller deems it to be deliberately misleading? Experts say it's possible it could be part of the obstruction puzzle.

Jonathan Turley is a constitutional law expert at George Washington University who testified at Clinton's impeachment hearings. He said that, while not all presidential lies are crimes, “lying to the American public can be evidence of crimes like obstruction. ... Clearly an order to fire Mueller would fit easily within the obstruction narrative and would be material to any consideration of either an indictment or impeachment.” But Turley added that he didn't think such false statements to the public by themselves would necessarily be “indictable.”

Another constitutional law expert, Mark Tushnet of Harvard University, said it would be a “stretch” to say that such lies inherently violate a president's duty to faithfully executive the laws. But he said it could play into an obstruction case.

“Starr doesn't quite say that, standing alone, the false statements to the public violated the 'take care' obligation,” Tushnet said, “but that they were part of an overall pattern of events that amounted to such a violation — which, in context, I think is, or is close to, saying that the overall pattern was one of obstruction of justice.”

He added: “My view is that a president can be impeached for serious political misconduct that is, as I put it, in the neighborhood of a serious criminal offense. And a pattern that includes deliberate and unjustifiably false statements to the public can (though it doesn't have to) count as satisfying that standard.”

Michael Gerhardt, a former Clinton aide and impeachment expert at the University of North Carolina, said the false denial at the very least cuts into Trump's credibility, even if it wouldn't be the biggest part of an obstruction case.

“His denial obviously suggests he is trying to hide the fact he was considering this, but if he lies under oath about it then he has a much bigger problem,” Gerhardt said. “At the very least, his denials once again put his veracity on the line.”

And of course, the ultimate arbiter of all of this is likely to be Congress. Mueller could include lies told in public in his report, like Starr did, but Congress has the power to decide whether to impeach for such things.