Above all else, my strongest impression was that the candidates lived in entirely different universes. In one universe, Hillary Clinton has committed crimes of unprecedented severity, the Clinton Foundation is crooked to the core, the Democratic Party is a vast criminal conspiracy rigging the election, and all accusations the Trump groped women are debunked lies invented by the Clinton campaign. In the other, the Russians are interfering in our election and treating Trump as their (presumably) unwitting puppet. Partisans of either side have decided which universe they live in. I have no idea what political bystanders will make of it all.
At the beginning of the debate, Trump seemed a bit Palin-esque, particularly about the Supreme Court. It had the feeling of a debate between a candidate who knew what she was talking about and one who was spouting canned talking points, mostly about the Second Amendment.
Later on, Trump reverted to form, citing very convincing-sounding but false facts and starting to lose his temper, though interrupting less. Clinton smiled in a superior sort of way and was sometimes worth listening to, sometimes empty blather.
Both candidates showed considerable skill about changing the subject when a question got uncomfortable.
Trump did make a few good points, most notably about the folly of backing rebels you don't know anything about. True! On the other hand, his overuse of superlatives gets annoying fast. You just won't believe how annoying it is. In fact, Trump's overuse of superlatives is the most annoying habit of any politician in the history of this country!
But by far the most important moment of this debate was when Trump was asked if he would respect the outcome of the election and he said he hadn't made up his mind yet.
Here is my prediction on that. I doubt that Trump did anything impressive enough to create a large-scale swing in his favor tonight, so I think he will lose the election. I am guessing that when he does, one of two things will happen. Either his campaign staff will put a concession speech up on the teleprompter and force him to read it, at gunpoint, if necessary. Or else he will refuse, his staff won't be able to force him, and they will have no choice but to handcuff him, stuff something in his mouth, and lock him up in the closet with Mike Pence reads the concession speech. I am being hyperbolic here, of course, but you get the general idea. Either way, for the next few days he will go on an unhinged rant trying to walk the speech back and convincing everyone within hailing distance of reality that this is not anyone we want anywhere near the Oval Office. How many people are not within that distance is something I fear to speculate about.
On the comforting side, we are seeing the limits of how far the Republican leadership is willing to go. They will go to a lot of appalling places, but they won't go there. Impugning the integrity of the electoral process is a bridge too far, presumably because they know that once you impugn the electoral process, the whole democratic experiment really does face mortal danger. The bad news is that it is far from clear how many of their followers agree.
And that, of course, is why I have included this post under my "failures of democracy" label.