Gail Collins: Bret, I’ve had a lot of these conversations over the years, but I cannot remember ever starting one by asking whether you think the president is off his rocker. In the real, mentally ill sense.

Bret Stephens: Um, was he ever on his rocker, Gail?

Look, I’ve gone back and forth on this question. If you look up old interviews he conducted 20 or 30 years ago (check out this video of his testimony to a congressional committee in 1991), what you find is a much more coherent thinker and verbally acute speaker than the man he is today. I’m not expert enough to say at what point mental decline slides into senility or dementia, but there’s clearly been a decline.

Gail: Agree. But a lot of that is just arrogance. If you’d told the younger Donald Trump he was a future president of the United States, I doubt he’d have bothered to be coherent back then, either.

Plus in that congressional testimony he was reading prepared remarks, which always work better for him. Only problem is now he’s so full of himself he can’t stick to the script.