We know from past debates that the winner of the post-debate spin is as important as the winner of the actual debate. We know many people will not watch the entire debate, or any of it, so their opinions will be shaped to an outsize degree by the media reaction and "snap polling" afterward. In that sense, Hillary Clinton won twice — once in the debate and the other in the post-debate discussion. Here's what we have learned:

1. Donald Trump ironically lacked "stamina" and got progressively more incoherent and short-tempered as the night wore on. He dumped a post-debate appearance, slinking back home to Manhattan.

2. The Trump people know they lost, too. Trump entered the "spin room" personally, a first in presidential debates. Unwilling to let his debate performance stand on its own, he desperately tried to turn the page to a new set of Trump comments. It did not work. Worst of all, Trump surrogate Rudy Giuliani hinted that Trump might not show up for another debate. "If I were Donald Trump, I wouldn't participate in another debate unless I was promised the journalist would act like a journalist, and not an ignorant fact-checker," he declared. That's the way a loser talks.

{"type":"video","title":"Dallas News Video","author_name":"Dallas News","_id":"81b3g0NjE6ElWw_SWiVMcVzhu7Nz8jfF","provider_name":"Ooyala","html":"

","providerType":"ooyala","providerLink":"http://www.dallasnews.com/oembed","embedType":"video"}

3. The media reaction — both mainstream and conservative, in print, online and TV commentary — has been brutal. Although of limited value, focus groups in Florida and Pennsylvania and post-debate snap polls heavily favored Clinton. #NeverTrump conservative Bill Kristol tersely said, "I'm not positive Hillary actually won the debate. But I'm sure Trump lost it. He choked." His more Trump-sympathetic colleague Fred Barnes panned Trump's performance: "He talked too long, interrupted Clinton, touted himself, and took her bait time after time to respond to her charges. It was the wrong approach at the wrong time at the wrong debate." Huffington Post's Howard Fineman called it "the worst — and I mean worst — debate performance in modern times," graciously allowing for the possibility that some pre-modern debater was forced to flee the stage under a barrage of rotten fruit. "Starting around the 11-minute mark in the 95-minute event, Trump's cool began to melt," The Washington Post reported. "He started to shout through Clinton's answers, gripping the sides of the lectern until his hands turned red." The Associated Press chimed in: "If Clinton aimed to get under Trump's skin in the first 30 minutes of the debate, the Democratic nominee appeared to succeed. Clinton often put Trump on the defensive, saying he had 'rooted for' the collapse of the housing industry and had considered climate change to be a hoax. In another exchange, Clinton said, 'I have a feeling that by the end of this evening I'll be blamed for everything that ever happened.' "

4. Trump really is not capable of studying issues, mastering facts and educating himself even with the presidency on the line. He'd like us to believe he doesn't need to — that "overpreparing" is bad. (Clinton turned this against Trump in one of her better one-liners: "And you know what else I prepared for? I prepared to be president. And I think that's a good thing.") Trump has shown himself to be too arrogant or too intellectually challenged to learn things — maybe the most dangerous trait for a president.

5. Trump proved that he lacks impulse control. He knew he had to seem levelheaded and yet couldn't stop himself from interrupting. The split screen worked to his disadvantage, showing him smirk and grimace while Clinton remained cool as Trump served up one word salad after another.

6. Trump added to concerns about his racism and misogyny. He inexplicably defended his foray into birtherism, allowing Clinton to say flat-out that this was a "racist lie." After Clinton recited some of the insults he launched against a Hispanic beauty pageant contestant, Trump on Fox and Friends made his cruelty and disdain for women that much clearer: "She gained a massive amount of weight, and it was a real problem." His worst answer of the night might have been his defense of a case brought against him alleging housing discrimination in the 1970s. "And we, along with many, many other companies throughout the country, were sued. We settled the suit with no admission of guilt. Zero." So everyone did it, and he didn't have to confess?

{"type":"video","title":"Dallas News Video","author_name":"Dallas News","_id":"NnMG00NjE6XuEobydq83RVP0bx6003Lo","provider_name":"Ooyala","html":"

","providerType":"ooyala","providerLink":"http://www.dallasnews.com/oembed","embedType":"video"}

7. Fox News got embarrassed, and rightfully so. Trying to insist that he had opposed the Iraq war from the start — he did not — Trump pleaded with the audience to call Sean Hannity, with whom he claims to have discussed the matter (off air, of course). That's an extraordinary recognition of the degree to which Hannity — and thereby Fox — has been made into an adjunct of the campaign, when you think about it. Fox's legitimate news people should raise a rumpus; Hannity is undermining their brand.

8. Clinton did not need to bare her soul. Sure, she could have been more revealing of her inner life and more emotional. But she won the debate by doing what she feels comfortable doing — preparing tenaciously, crafting rueful barbs and embracing her opponent's insults to highlight her own tenacity. She earned the right to invoke Michelle Obama's admonition (unlike Melania Trump, Clinton didn't claim the first lady's words as her own): "When they go low, we go high."

Jennifer Rubin is a conservative blogger for The Washington Post, which first published this column. Twitter: @JRubinBlogger