"Chaos." "Painful." "Dispiriting." "The worst presidential debate in American history." "The lowest point in American political culture in my lifetime."

You get the idea. These are responses, from Donald Trump supporters and Donald Trump opponents, to the first 2020 presidential debate Tuesday night. I detect a note of shell shock and sickened recoil from the partisans of both candidates, greater than I've ever noticed before.

Some of us can remember when debates were decorous, when candidates spoke respectfully of each other and sometimes granted each other's good faith. A more contentious tone and dismissive attitude toward opponents appeared in the first baby boomer debate, between then-Vice President Dan Quayle and his successor former Vice President Al Gore in 1992 (both younger men than Donald Trump or Joe Biden).

A similarly contentious VP debate came in 2012, when then-Vice President Joe Biden pummeled challenger Paul Ryan with constant interruptions, raucous ridicule and scornful laughter. Which wasn't greeted, as I recall, with the lamentations we see now from much of the press.

On Tuesday, Trump subjected Biden to similar treatment, and Biden responded with contempt and colloquial jibes. When Trump pressed him to answer moderator Chris Wallace's reasonable question of whether he'd pack the Supreme Court with additional justices, Biden replied, "Would you shut up, man?"

In CBS' snap poll, 48% said Joe Biden won the debate, and 41% said Donald Trump did. That's almost identical to the 49% to 43% lead Biden holds in the RealClearPolitics average of recent polls. So perhaps the debate made no difference. Or perhaps both candidates' supporters were equally likely to watch and say their man won.

Both candidates seem to have carried out, in rough-and-ready style, their or their campaign managers' strategies.

The obvious Biden strategy was to stay cool, make no mistakes and show no sign of cognitive impairment -- as he has occasionally showed on the campaign trail. This is in line with a campaign schedule that, even granting the need to adjust to the COVID-19 pandemic, is the opposite of strenuous. The idea is that he's ahead and shouldn't risk blowing his lead.

The Biden campaign has called an early-morning "lid" -- an announcement it will make no news -- on at least 11 days in September. Early lids were common in Ronald Reagan's August vacations to his ranch in the mountains above Santa Barbara. They're less common -- though occasionally required for debate prep -- in the September before the election.

Biden has been blatant about not taking a stand on Supreme Court packing: He won't take one because it might be an issue, something voters might consider, to his detriment, before the election. Let them wait till later. Similarly, he says he doesn't favor the Green New Deal and then says, astonishingly, that it would pay for itself. He's been for and against fracking. He blames Trump for the recession while suggesting he's for longer lockdowns.

He's not the first non-incumbent candidate to straddle issues or misstate facts. And Biden supporters are so sure that Trump always lies that they wouldn't put up their umbrellas if he said it was raining.

The obvious Trump strategy is to employ Biden's 2012 tactics against Ryan: constant interruptions and loud ridicule in the hope of rattling the older candidate and eliciting an incoherent response or a lapse in concentration. But Biden doesn't seem to have cracked. As National Review editor Rich Lowry tweeted, "I agree with everyone who says the debate is hard to grade on any traditional scale, but the key takeaway is that Trump set out to make Biden crack and it didn't happen."

Perhaps there was another goal to this strategy. Pollster Frank Luntz, conducting perhaps his millionth focus group, reported that some participants found the debate so unpleasant that "it actually made them less likely to vote for any candidate." That could work to Trump's advantage. His support, always under 50%, stays solid above 40%.

His 2016 victory was possible because neither major party nominee got the votes of 6% of the electorate -- the highest percentage since 1980 and 1968. So it's to Trump's advantage to turn soft Biden supporters into third-party voters or non-voters entirely. A contentious, chaotic, painful debate may be one way to do that.

Ultimately, the most powerful argument is that they're not the other guy. Trump's repeated failures to make his own case intelligibly and Biden's unembarrassed refusals to take stands on key issues: Chaotic. Painful. Dispiriting.