Pete Buttigieg is running for president of the United States. Yep, he’s one of the hundreds of Democrats seeking to defeat Donald Trump in 2020.

Who is this young man? He’s the mayor of South Bend, Ind.; he calls himself a progressive; he’s openly gay.

He also wants to know a thing or two about Vice President Mike Pence, a fellow Hoosier who once was governor of Indiana.

Buttigieg acknowledges the vice president’s devout Christian beliefs and wonders how the VP can serve with what he calls a “porn star president.”

You know, that’s a good question. It’s one that I’ve rolled around in my noggin ever since Pence agreed to be Trump’s running mate in 2016.

The two of them comprise one of the more unlikely political tandems in recent history. I don’t doubt Pence’s religious sincerity. He has a policy of avoiding being in the same room with women other than his wife, Karen, without at least one other person present. He is the straightest arrow in the quiver.

Yet he serves with a president who, shall we say, is damn near the polar opposite. Oh, sure, Trump panders to the evangelical movement, but really . . .

Does he walk the walk of a man of deep faith? C’mon. Let’s be real. You’ve seen and heard how he comports himself in public. You’ve heard the language he uses. You all know about his acknowledged infidelity with two of his three wives; and, yes, we have credible allegations of the same conduct involving wife No. 3, the first lady of the United States.

Buttigieg wondered recently, according to CNN: “How would he allow himself to become the cheerleader for the porn star presidency? Is it that he stopped believing in scripture when he started believing Donald Trump?” Buttigieg said. “I don’t know. I don’t know.”

I’ll repeat: I don’t doubt Pence’s devotion to his faith.

However, it is fair to ask out loud about the vice president: How do you square your straitlaced reputation with that of a man who demonstrates constantly the amorality of someone with zero spiritual grounding?

Therein might lie a flashpoint as this 2020 campaign season reaches warp speed.