Trump Derangement Syndrome (TDS) doesn’t just affect masses of far-left students and protestors and media ambulance chasers.

It may have affected Joe Biden.

At a New Hampshire campaign stop, this weekend, he fielded a “good question” from a young woman studying economics, who challenged his electability. As he turned away he denied she’d ever been to a caucus before, and, chuckling, called her a “lying, dog-faced pony soldier.”

Bizarre.

Biden’s old, and it is possible that his unhinged loopiness is the result of some sort of dementia or swiftly decreasing mental capacity. I wouldn’t want to make fun of that any more than I’d want to vote for someone even plausibly diagnosed with a brain malady.

But it’s possible that Biden’s been spooked by the incomprehensible-to-him success of Donald Trump.

Trump seems to say whatever he wants, breaking normal bounds of decorum and accepted standards of linguistic prudence, and get away with it.

Could Biden’s increasingly frank and unguarded statements make sense in this context?

Maybe it’s not diminished capacity in the pre-frontal cortex, but a license to say damn near anything.

Can Biden afford such a strategy? Whatever it is that Trump does, successfully, has not been duplicated by any of his would-be competition. Not without seeming clumsy and kind of stupid.

The Biden camp says the current bizarrerie, “lying, dog-faced pony soldier,” is from a John Wayne movie. Apparently it’s from a Tyrone Power flick.

Hollywood scriptural references aside, Biden’s substantive answer to the electability question is that he has more black support than his competitors, and that you have to take the first four primary states as a whole.

A reasonable answer and not suggesting dementia.

TDS remains a possibility, then.