It has come down to this.

A former vice president of the United States, Joseph R. Biden, spoke to a Miami conference and said if Donald J. Trump and he were in the same high school, he would “beat the hell out of him.” The issue on the table dealt with the treatment of women by men.

So, what does the president of the United States do? He responds via Twitter (naturally, yes?) that “Crazy Joe” lacks emotional and physical strength and that he — Trump, of course — would take him out. Here is Trump’s tweet: “Crazy Joe Biden is trying to act like a tough guy. Actually, he is weak, both mentally and physically, and yet he threatens me, for the second time, with physical assault. He doesn’t know me, but he would go down fast and hard, crying all the way. Don’t threaten people Joe!”

I do not know which is worse: the former VP saying out loud that he would beat up the president or the head of state responding via social media with a “so’s your mama!” retort.

This is the kind of stuff one usually sees occurring between middle-schoolers. It’s a close call, but I’ll give the “raspberry” in this exchange to the president.

He is the one who occupies the office that, in an earlier time, used to command decorum, dignity and discipline. The former vice president is known to be a bit loose of lip at times; but this is the first time I’ve ever heard Biden actually state a desire to do physical harm to another public figure.

Trump, though, actually has extolled the virtue of beating someone up, such as what he has said about demonstrators who showed up at his political rallies. That, however, occurred before he won the election and took the presidential oath of office.

Donald Trump promised many times he would be “more presidential” once he took that oath.

Well, so much for promises.