I’ve wondered about this for nearly as long as Hillary Rodham Clinton has been in public life — which seems like forever.

Why do the media, the political class, historians and Mr. and Mrs. J.Q. Public refer to the Democratic nominee for president as “Hillary”?

I’ll admit to doing it in casual conversation. My wife and I talk about this election all the time. We’re caught up by it. We’re enthralled — if that’s the right word — by all of its patently bizarre twists and turns.

Then I’ll toss out something like this: “Did you hear what Hillary and Trump said today?” My wife identifies the two major-party candidates the same way.

The Republican nominee doesn’t get the same air of familiarity, if that’s what it is. We refer to Donald J. Trump as “Trump.” I’m inclined to use more, um, descriptive terminology at times. And yes, I’m quite sure those on the other side attach the same pejorative qualifiers to Hillary.

See, there I go again … falling into that first-name trap.

I mean no disrespect. I take her as seriously as I do any other politician, male or female.

I’ll admit to using first names on other pols. Newt, Mitt and Jeb are my favorites. Their names are unusual enough that you don’t need to last names to know about whom one is referring. It’s kind of like Wilt, Arnie, Tiger and Kareem … you know?

There’s got to be a psychologist out there who can explain it to me.

Hey, do you think Dr. Phil might be looking for a topic to cover on his TV show.