The Democratic presidential field is currently so crowded with candidates that it is difficult for televised debates to be anything but a frenzied spectacle.

Harris attacks Biden's record on race in Democratic debate's key moment Read more

Thursday night’s debate in Miami wasn’t exactly substantive. Nor was it elevated. But it was reliably entertaining, far more so than Wednesday’s debate (on which our broken clock of a president had an accurate take). And it did provide useful insight into the differences among the candidates and how the race might unfold.

The two most obvious observations are: Joe Biden performed miserably, while Kamala Harris was in excellent form.

The standout moment of the night was a jaw-dropping exchange between Harris and Biden on segregation and busing. Harris told Biden that she had been hurt by his nostalgic recollections of relationships with racist senators. She pointed out that he fought against busing in the 1970s, an issue that was deeply personal for her, as she had been bused as a child. She spoke movingly about the pain caused by Biden’s stances.

It was an opportunity for Biden to show some thoughtfulness and contrition over one of the ugliest parts of his political history. He did not take that opportunity. Instead, he accused Harris of smearing him: “It’s a mischaracterization of my position. I did not praise racists.”

But Biden has indeed praised racists – he gave a glowing eulogy at the funeral of infamous segregationist Strom Thurmond. Biden then had the audacity to frame his opposition to busing as a “states’ rights” issue; he had not opposed busing, he said, merely the federal government’s attempt to force racial integration.

Quick guide Who are the leading Democrats running for 2020? Show Hide Joe Biden, former vice president Biden unsuccessfully ran for the nomination in 1988 and 2008, and his campaign is likely to be dogged by controversy after allegations from several women they were left feeling uncomfortable by their physical interactions with him. If successful, Biden would become the oldest person to be elected president in US history. Mike Bloomberg, former New York mayor Bloomberg has expressed concern that none of the top candidates can defeat Trump, and he aims to make up for an unusually late entry in the Democratic primary with historic spending of hundreds of millions of dollars in television ad time and an unorthodox strategy of skipping the first four states in the primary. Bloomberg has announced that his campaign will be entirely self-funded, but can this billionaire win? Amy Klobuchar, Minnesota senator On Election Night 2018, Klobuchar coasted to a third term as senator in a state Trump almost won. Next morning she was on every short list of potential presidential candidates. Supporters say her success with rural voters makes her a formidable candidate in the Rust Belt, while her calm demeanour provides a clear contrast with Trump. Bernie Sanders, Vermont senator Sanders turned a long-shot, anti-establishment bid for the presidency into a “political revolution” that energized the party’s progressive base. His political career began nearly 40 years ago, but it wasn’t until his 2016 run that Sanders became a national figure as a new generation of Democrats – and 2020 contenders – embraced his populist economic policies. Elizabeth Warren, Massachusetts senator Her sharp criticism of Wall Street and big corporations has made Warren a favorite among progressive activists, and she will campaign on a message of a rigged economic system and income inequality.

Harris forcefully rejected this spin, noting that the whole point of federal action on civil rights is to override the inaction of racist local governments. But she could have gone further. Biden was simply lying about his history. He had actually said that “busing is a bankrupt concept”, and recently-revealed documents show he actively sought the support of segregationists on the issue.

It’s not surprising that Biden declined to apologize to or even empathize with Harris. As a general rule, Biden does not apologize, even for egregious remarks. “I’m not sorry for anything I have ever done,” he has said. He also declined on Thursday to clarify or reframe his recent remark that “nothing would fundamentally change” for the wealthy if he became president. He reaffirmed that he is offering a backward-looking politics that wishes to “restore the backbone of America”, making the absurd claim that Donald Trump is the “only president in our history” who has “equated racists and white supremacists with ordinary and decent people” and “engaged and embraced dictators”. (Has he ever read a book on American history?)

It’s still not actually clear whether this tendency will hurt him. In a way, it’s all part of the “Biden brand”, and older voters may not be repulsed in the way that younger and more progressive factions in the Democratic party are.

Yet even those most blasé about Biden’s tendency to make appalling remarks (and then double down on them) will be disappointed by his debate performance. Much of the time, he seemed lethargic, almost indifferent.

Harris, on the other hand, was confident and pressed her case with verve. She spoke vividly about the consequences of climate change and the lives of immigrants and challenged Biden on the Obama adminstration’s deportation record. (Unfortunately, her actual record on immigration somewhat departs from her stirring humanitarian rhetoric, and she has shown a willingness to fabricate her history on the issue.)

It also became clear that Harris is now presenting herself as firmly on the “Sanders left”. She was the only candidate other than Sanders himself to advocate eliminating the private insurance industry, and condemned the influence of the rich and powerful more aggressively than almost any other candidate. Harris’ economic populism may be difficult to swallow given her history, but it’s clear that she intends to compete for the supporters of Sanders and Warren.

Play Video 3:27 US election 2020: highlights from second night of Democratic debates – video

Bernie Sanders was his usual self, thunderously denouncing America’s grotesque inequality. His performance was neither outstanding nor disappointing. Sanders’ best moment came during the debate’s brief section on foreign policy, where he highlighted his opposition to the Iraq war, his success in getting the Senate to end US support for Saudi Arabia’s bombing of Yemen, and the need to maintain peace with Iran. He forcefully defended abortion rights, but missed an opportunity to talk about racial justice.

He was, as usual, needlessly cagey on the question of whether Medicare For All will raise people’s taxes. He should get better at stating up front that it will, and then discussing why people still come out ahead on the bottom line, rather than appearing to have something to hide. He also gave a frustratingly vague answer on how he would implement Medicare For All, saying that he’d implement it by mobilizing a social movement. It would be nice if he pointed out that there are serious policy thinkers who are working on the design and funding of single-payer healthcare. Otherwise he makes room for critics who say he is impractical and utopian.

Few of the other candidates got much of a chance to distinguish themselves. Pete Buttigieg was polished and articulate, especially as he talked about how his military background informed his support for stricter gun controls. But, in a Democratic field overstuffed with bland white guys, he needed to live up to his hyped reputation as a political wunderkind. That he didn’t do, and he was somewhat blindsided when Eric Swalwell (of all people) effectively challenged him on his failure to discipline his municipal police chief and his misleading remarks about his power to do so.

Andrew Yang briefly plugged his basic income scheme, but was given little airtime. John Hickenlooper was most effective when emphasizing specific accomplishments in government, but lapsed back into lazy warnings about “socialism”. Swalwell distinguished himself mostly by the number of times he demanded that we “pass the torch” to a new generation. Michael Bennet did not say a single memorable word. Kirsten Gillibrand appeared to be reading every sentence from a teleprompter, though it was impossible for this to be the case.

Marianne Williamson gave the most “unique” answers. Asked about her first policy priority, she said she would make a congratulatory phone call to the president of New Zealand. Her closing statement was a somewhat charming tribute to the political importance of love. These will get her labeled something of an eccentric, but she also made the most powerful moral case against the Trump administration’s immigration policies, calling them “collective child abuse” and making the important point that “if your government does it that doesn’t make it any less of a crime”.

The candidates were generally impressive in their pro-immigration sentiments. Joe Biden was caught off guard when he was asked why the Obama administration had deported so many millions of people. On a day when prominent Democrats have capitulated on the issue, it’s not clear how many of them will back up tonight’s words with substantive commitment to immigrant rights.

The debate had so many speakers and so many issues in so little time that not much could happen beyond crosstalk and quick bursts of campaign rhetoric. At least climate change was discussed, albeit briefly. None of the candidates from the “back of the pack” did much to move forward. Harris certainly proved that she may be a formidable challenger to Sanders and Warren, not to be underestimated. Biden showed himself unprepared and vulnerable, though it’s not clear how it will affect his support. He affirmed that his politics are retrograde and ignorant of the urgency of racial and economic justice.

Sanders continued to draw the debate in the right direction, emphasizing the struggles of working people and the need for sweeping, rather than piecemeal, political change to build a better and more just society.