Katy Tur demands answers: “What is going on with him? ... Has the president lost a step?”

Some of Donald Trump’s claims over the past few days are so bizarre that they appear to go beyond simply lying, and raise questions about his mental faculties — a concern that numerous doctors and psychologists have raised.

This week, Trump suggested the “Access Hollywood” tape of him boasting about assaulting women was fake — even though he previously admitted it was real, first dismissing as “locker room talk” and then apologizing for it. He also revived his racist suspicion that President Barack Obama’s birth certificate is a forgery in private conversation with a senator — even though, again, he already admitted it was real last year and even tried to take credit for proving it.

To MSNBC’s Katy Tur, this was not just bluster, but evidence of a much deeper, more serious problem with Trump — a possibility she raised in conversation with the Washington Post’s Philip Rucker:

RUCKER: I talked to a number of advisers, both inside the White House and outside, and nobody quite understands what the president did. It was not part of any sort of strategy to raise awareness about border policy.

TUR: What is going on with him? Because not only this, Phil, he is questioning whether or not — you know, he’s trying to throw doubt into the Access Hollywood tape, something he’s already admitted to and apologized for. According to the New York Times, he’s also once again trying to question the legitimacy of President Obama’s birth certificate, something that he, again, had to fess up to during the campaign, saying that President Obama was born here. I mean, is it OK to ask the question, is the president losing a step? What’s exactly going on, Phil?

RUCKER: Well, a number of people are asking that question and his critics are saying, look, he’s creating this alternate reality, he’s — he’s taking facts that are already very clear, which is — that Access Hollywood video, it is on tape, he’s already admitted it was him, Billy Bush got fired for it — and sort of recreating in his mind, well, maybe it’s not me, maybe it doesn’t sound like me, does it sound like me? He’s been asking people whether it sounds like him.

“Creating an alternate reality” is not something a normal person does in day to day dealings with other people, let alone in politics. It could have deadly consequences when major foreign and domestic policy is on the line — and all of this is occurring against the backdrop of North Korea’s latest missile test.

Like Tur, all Americans should be concerned about the stability of our leader — and based on Trump’s erratic behavior and claims, there’s more reason than ever to be concerned.