On Tuesday night, 12 candidates crammed on to the stage at Ohio’s Otterbein University. It was the first time that so many Democratic presidential hopefuls have shared the same stage on one night.

But the attention was almost all focused on one candidate, the Massachusetts senator Elizabeth Warren, who has emerged as the frontrunner after a slow and steady rise in her support, and who has crystallized her position in recent months as the party’s intellectual and ideological center of gravity. Questions were framed around her policy positions, her past statements, her agenda; other candidates staked their claim to positions almost exclusively in relation to where Warren stands.

Even on the rare occasions when Warren was not speaking, not directly being spoken to, and not being spoken about, her dominance hung over the conversation, making itself known in unexpected moments. At one point, a moderator, CNN’s Anderson Cooper, addressed another contender – the Minnesota senator Amy Klobuchar – by Warren’s name. Klobuchar smiled and graciously deflected, but within minutes, she was bringing up Warren herself.

Warren’s new dominance reflects not only her slow but dramatic rise in the polls, where she is now besting the longtime establishment favorite, Joe Biden, but also a renewed Democratic political landscape in the wake of the opening of an impeachment inquiry against Trump in the House of Representatives. At the debate, the impeachment proceedings provided a brief opportunity for unity among the ideologically divided candidates, with a softball opening question about the inquiry providing all of them an opportunity to voice their distaste for Trump. But the unity ended there. From that point on, half of the stage dedicated themselves to the project of attempting to discredit Warren.

Trump, abortion and attacks on Warren: the Democratic debate's key takeaways Read more

She was attacked by Klobuchar and Pete Buttigieg over how she plans to pay for Medicare for All. She was attacked by Andrew Yang over her plan to break up big tech and enforce a strict antitrust agenda. She was attacked by Kamala Harris, who alleged that Warren was hypocritical for, of all things, not calling on Twitter to suspend Donald Trump’s account. She was attacked by Joe Biden for supposedly being “vague” on Medicare for All. She would have been attacked by Tulsi Gabbard for her lack of military experience, except Gabbard was cut off by a moderator.

For the most part, Warren weathered these attacks with patience, grace, and an agility in her rhetoric that rivals that of a gymnast on a balance beam. She refused to take the bait repeatedly offered to her by moderators and other candidates, who attempted to goad her into saying that she would raise taxes to cover Medicare for All. This denied her opponents a video clip that they could use to discredit her; instead, she hammered home the larger point that total costs would go down under her plan. She refused to get mired in the petty point of whether Twitter should suspend Trump’s account; instead, she focused on how big tech companies have too much influence over our politics to go unregulated. She wouldn’t concede Andrew Yang’s dubious assertion that unregulated tech giants encourage innovation; instead, she focused on the ways that monopolies in all sectors of the economy – she cited agriculture and pharmaceuticals – need to be broken up to protect consumers.

It was a frontrunner’s strategy, a deflection technique meant to avoid inconvenient commitments and stymie the attack strategies of her rivals. Warren made moral cases instead of economic ones, refusing to get bogged down in the kinds of specifics that can only be communicated poorly and haphazardly to voters within the confines of the contentious debate format. To make her case in a general election, she will have to become more willing to communicate the details of her multitudinous plans on a mass scale, more ready to get down to brass tacks on television and on the debate stage. But Tuesday’s debate was her first as the object of rivals’ ire – before tonight, her opponents had more or less held their fire against her. The discipline and poise she showed in this new role bodes well for her performance in a general election against the erratic and taunting Trump. He will bait her and goad her, and she will be able to calmly and convincingly remain on message.

Other candidates, meanwhile, shifted their strategies in the wake of the new political circumstances. Buttigieg was newly combative, displaying a strategy of attacking the more progressive wing of the party that he had debuted in a series of left-punching statements made in the days before the debate. He criticized Warren on her wealth tax and on Medicare for All, which he deemed impossible; he criticized the former Texas congressman Beto O’Rourke for his call to institute a nationwide buy back for automatic weapons, a prospect that Buttigieg deemed a “shiny object”. The message was that better things are not possible, and that Democrats, and Americans more broadly, must lower their hopes. It was hardly an inspiring assertion, especially considering that Buttigieg delivered it with sneering condescension, apparently impressed with his own callous brand of pragmatism. The combination of cynicism, contempt, and Buttigieg’s extreme youth was disquieting. The South Bend mayor’s debate performance conjured the image of a character in a dark teen drama, an ambitious prep school debate captain who would throw his best friend under the bus in order to secure his own admission to Princeton. In reality, Buttigieg graduated from Harvard.

Not everyone performed so poorly. Booker and Castro made dexterous pivots into auditions for the vice-presidential slot. Booker made pleas for civility and called on the candidates to unite against Trump; Castro made a concerted effort to expand the breadth of each question to include the concerns of marginalized communities, pointing out the role of police shootings in his answer to a question about gun violence and the role of class in response to a question about abortion rights.

Bernie Sanders, returning to the debate stage and effectively to the campaign trail after his 1 October heart attack, performed with a degree of mental acuity and physical vitality meant to convey that he is capable of continuing his run. After the debate aired, his campaign announced an endorsement from Congresswoman Alexandria Ocasio-Cortez, billed for a rally this weekend in Queens, New York. The heart attack seems to have in effect ended Sanders’ meaningful bid for the presidency – at 78, the concern over his health is not only severe but also greater than it would be for other candidates, and Sanders was falling in the polls before his hospitalization. But his fundraising remains robust – he led with nearly $25m last quarter, trailed narrowly by Warren – and he will not be exiting the race soon. On the debate stage, he signaled that he would be an advocate for progressive values throughout the primary contest and beyond. Sanders’ endorsement will be coveted by whoever wins the nomination, and he will have an unusual degree of power in determining that person’s agenda.

Still other candidates seemed nearly ornamental. Tom Steyer, the billionaire impeachment advocate who launched a vanity run in July, essentially bought his way into the debate, where he was largely decorative.

But the most notable irrelevancy of the night was Joe Biden. Supposedly the candidate to beat, he was remarkably quiet on the debate stage. He mostly observed when the other candidates attacked Warren and looked on absently as she parried their attacks. Over the three hours of the broadcast, the former vice-president was often silent, frequently incoherent, and never able to get through a talking point without fumbling a poorly memorized phrase or mispronouncing an unfamiliar word. It was hard to imagine him as the president. It was hard, even, to decipher what he was trying to say. Joe Biden is a bit taller than Elizabeth Warren, but standing at the lectern next to his, she looked 10 feet tall.