Brian Williams: Part two of round one of the Democratic debates is now history. It occurs to me that the most indelible picture of the evening is a photo we did not see, of a young girl named Kamala at the bus stop on her way to school. It was at that point, she forged a moment against the front runner, Joe Biden.
Nicolle Wallace: I think [the candidates] were all closer to the beating pulse of the hopes and desires of the most urgently desperate-to-beat-Donald-Trump wing of the Democratic party. Kamala Harris has not been showcased in a moment that did not elevate her. She changed the dynamics of the debate tonight.
Joy Reid: I think tonight the candidates… needed to give us a vision in our minds of what it would look like for them to debate Donald Trump. And the one person who did that was Kamala Harris.
She had a strategy, and the courage to attack Joe Biden. She destabilized him on the race question. And she did a bank shot off of Barack Obama — heresy in the Democratic party — on the deportation policy. It was brave and it went well for her. Harris presented herself as a front-runner tonight.
Lawrence O’Donnell: Sen. Harris went straight at Joe Biden. She knew she was going to do it. She did it well and strongly, using his history on school bussing. It’s hard to imagine that you’re in an election in the 21st century that refers back to the 1970s. She was powerful on immigration and other issues.
Steve Kornacki on Twitter: The Harris-Biden exchange seems like an obvious threat to his black support because of the topic, but the *way* he defended himself — choppy, aimless, ending with “I must be out of time” — could really advance the idea that he’s past his prime.
Kornacki (on air): Can Biden turn it around? Does this [debate] wake him up? If you get the same performance like that, as the race goes, I think that’s trouble for him.
Former Sen. Claire McCaskill: Kamala obviously had a big night. I do think Mayor Pete handled himself well, he showed that he deserves some of the attention he’s getting. Comparing his performance to Beto last night, he was substantively better. He delivered in a calm way and I could see him also debating Donald Trump.
Kirsten Gillibrand tried to almost do a de Blasio, trying to break in. But she ended up only with 7 ½ minutes of total time talking.
Really strong candidates. The party could start to decide which one is the one to take the mess in the White House out.
I don’t though know about [Marianne Williamson] calling the prime minister of New Zealand though. Huh?
Lawrence O’Donnell: I don’t think anyone up there had a bad debate. I think Joe Biden was overshadowed. It doesn’t mean the others didn’t do well.
Rachel Maddow: Not all of them can be front-runners, but nobody is going to walk away thinking they did poorly. They all performed.
Eric Swalwell, for example, the way he has taken on the gun issues is earnest and deep… he challenged Sen. Sanders, going after Pete Buttiegieg on the issue of body cams.
This is not a gloves-off primary anymore. It’s on substance. It’s not ad hominem. I think it’s good.
Wallace: For people who are excited about all 20 people they’ve seen over the last two nights, just about everybody helped themselves in some way. On that stage, there was a lot for everybody.
Watch the candidates’ closing statements here.