Some of the blame could go to Chris Wallace, the moderator from Fox News, for failing to take control of a debate undermined by Trump's constant interruptions and wanton disregard for the time limit. To be sure, Biden occasionally stepped on Trump's lines, though he generally refrained from taking Trump's bait.
But most of the blame must be assessed on the president of the United States who was out of control from the start. At one point early on, Biden seemed to be speaking for millions of Americans when he asked the perpetual interrupter Trump, "Will you shut up, man?"
Presidential debates have been a great exemplar of American democracy since 1976, when Jimmy Carter and President Gerald Ford squared off. Some of those debates have been pivotal, some have been less than entertaining, but each has been carried off with a level of substance and decorum that voters want and deserve from potential leaders of the free world.
Until Tuesday night.
There were almost too many lowlights to count, most courtesy of Donald Trump.
It was as if Trump were given one last chance to show that he had grown into the job of the presidency, that the gravity of his duties and acceptance of the need to represent all Americans would humble him. He clearly has not. No doubt his supporters may have loved his bully mode, but if there is such a thing as "Trump fatigue" — and if there wasn't before Tuesday, there is now — it's hard to imagine his debate performance will gain him any votes.