CNN broadcast a special the other night on the landmark debate series between two men vying for the presidency of the United States of America.

Democratic U.S. Sen. John Kennedy faced Republican Vice President Richard Nixon.

The special talked at length about the men’s preparation for the encounters and the consequences that they delivered to the U.S. electoral system.

If only we could return to those days when the most trivial thing we talked about was whether one candidate looked more robust than the other one.

These days, we’re talking about a lot of things that have pulled these joint appearances into the gutter.

The leading Republican candidate, Donald J. Trump, is fond of tossing insults out at his opponents. Lately, some of those foes have responded. One of them, young Marco Rubio, has introduced — in a round-about way — the subject of Trump’s sexual endowments.

We’ve heard comments about perspiration, watched Trump make fun of Rubio’s physical appearance, listened at Trump has called Ted Cruz a lying son-of-a-gun.

And then — from the peanut gallery — former GOP nominee Mitt Romney has weighed in with comments and questions about why Trump doesn’t release his tax returns; he’s also called Trump a “phony” and a “fraud.” Trump’s response? Romney is a loser, a has-been.

We are witnessing an absurd demonstration of petulance on a level many of us have never before witnessed at this level of what is supposed to pass for political discourse.

Fifty-six years ago, two men faced off in a series of three joint appearances. We were enthralled then just at the notion of watching them on live television. Those grainy black-and-white pictures now seem quaint.

The high-minded debate they engaged in, though, now looks statesmanlike, dignified, the kind of encounter one should expect to see between two individuals seeking to become the next head of state of the world’s greatest nation.

These days? It’s a clown show.