Kamala Harris excelled on Thursday night. Photo: Bloomberg/Bloomberg via Getty Images

Most weeks, New York Magazine writer-at-large Frank Rich speaks with contributor Alex Carp about the biggest stories in politics and culture. Today, the fallout from the first Democratic debates.

Over this week’s two nights of debates, the top 20 candidates in the Democratic primary have had a chance to introduce themselves to a national audience. Will anything they said winnow the field?

I am happy to answer with a resounding “Yes!” I’ll take a minor risk and guess that as of this morning, the field has been winnowed by more than half. We’re down from 20 to either seven (Biden, Sanders, Warren, Harris, Buttigieg, Castro, and Klobuchar) or nine, if you hold out hope that the mellifluous but glib bros Booker and Beto will start putting at least as much effort into bold policy positions as they have into their pandering effusions of gringo Spanish. Most of the rest were dead men and women walking before they arrived onstage, merely marking time until that inevitable moment when their political lifeblood — money — dries up. They will soon be forgotten, even if they’re not yet gone.

Like most everyone else, I did not see the Kamala Harris rocket takeoff coming before last night. Her ascent was easily the most energizing spectacle of the campaign thus far. And her rightly canonized exchange with Joe Biden wasn’t mere political theater — it was substantive. By linking Biden’s praise of James Eastland and Herman Talmadge to his opposition to busing, she revealed that Biden still doesn’t understand that he didn’t only benefit from these bigots’ supposed “civility” on legislative trivia back in the day, but actively enabled at least one plank of their arch-segregationist political strategy. He has chosen not to apologize for that failure. And last night, he paid a huge price by digging himself in further. His invocation in 2019 of states’ rights to argue against busing, a 1970s federal tactic to roll back the de facto school segregation that blighted students like the young Kamala Harris, sounds like something that would pop out of the mouth of Rand Paul, not a Democratic front-runner.

When Biden finally terminated that exchange, it was with his version of Jeb Bush’s “Please clap” debacle of 2016: “My time is up, I’m sorry.” He will continue to lead in the polls, for now, but it is only a matter of time before he finds another way to blow himself up. There were portents of Biden’s vulnerability last night beyond his exchange with Harris: his constant merchandising of his relationship to Barack Obama; his heavy reliance on an old script (“A job is a lot more than a paycheck”); his swings between wound-up Uncle Joe rhetorical overkill and improvisational rustiness. (Sanders is much more practiced at recycling his greatest hits.) For more than three decades, every Biden presidential run or prospective presidential run has run aground, culminating with his last in 2008, when he dropped out after drawing only one percent of the vote in the Iowa caucuses.

There was much more to Harris than her Biden face-off. She had sharp, unambiguous answers to every policy question. She was concise. She occasionally smiled and laughed (a card not played by any of the other 19 candidates). And she constantly reminded us that she was a prosecutor not just by saying so, but by showing off her talent. There may be no word that Trump fears more than “prosecutor,” and no professional expertise that the Democratic base is more eager to see inflicted on him. At a juncture when Trump defends himself against a charge of rape by sliming women who are not his “type,” Harris’s emergence could not be better timed. She is not his “type,” heaven knows, and, not unlike her fellow San Franciscan Nancy Pelosi, she is not a “type” he knows how to deal with at any level, whether on Twitter or a debate stage.

I hunger to see Pete Buttigieg on a debate stage with Mike Pence. No Democratic politician has ever been so skilled at tossing the Christian card right back at the likes of right-wing religious hypocrites and homophobes. Buttigieg also implicitly took down Biden when he apologized for his own failure in highly charged racial politics rather than denying his record. Did Biden take it in and learn anything? I doubt it.

A few points about the other contenders. In the first debate, Elizabeth Warren was the most prepared and cogent candidate by far. To me, her Achilles’ heel as a candidate could best be seen in her dodge of the gun-control question, in which she talked about the gun epidemic as a “serious research problem” on which we must “bring data to bear.” The truth is that we have plenty of data, all of it horrific, and accruing by the day. Her bloodless answer reminded me of the legendary debate shortfall of another brainy Massachusetts Democrat, Michael Dukakis. It’s in moments like these when Warren’s evident humanity and inspiring hardscrabble Oklahoma biography are buried under the Harvard professor; when “I have a plan for that” — or in this case “I will have a plan” — becomes self-referential shtick. In a country where almost no one, Democrats included, has read the Mueller report, most candidates’ plans will go as unread as Hillary Clinton’s. Warren’s plans may be the best-laid, but that might not be enough.

What struck me about Amy Klobuchar on Wednesday night is that, given how quick-witted she is spontaneously (e.g., the Kavanaugh hearings), her delivery of canned lines (“all foam and no beer;” “I don’t think we should conduct foreign policy in our bathrobe at 5 in the morning”) is not necessarily a plus for a politician who prides herself on a down-home lack of pretense. But a far more important debit was her unwillingness to directly challenge Warren (and by implication Sanders) on policy disagreements despite the openings the questions gave her to do so. “Minnesota nice” can only take you so far in a fiercely competitive political race.

As for Julián Castro, he not only demolished Beto for his lack of preparation on his signature issue of immigration, but was consistently thoughtful and engaging no matter what the subject. He was the only candidate in the first debate that you wished you’d heard more from. The reverse was the case with those bringing up the rear, even if they didn’t get a chance to say much. But while I can’t say I’ll miss the “look-ma-no-tie” former Silicon Valley executive or the insufferably vain mayor of New York, Marianne Williamson is so determinedly on her own idiosyncratic wavelength that her debate performance could be rated a success if viewed as a highly rated audition for a reality show. Or in her case, semi-reality.