Along the way, two new dynamics shaped the evening.

The first was the degree of critical focus on Sen. Elizabeth Warren, reflecting a calculation that she, rather than former Vice President Joe Biden, has the momentum in the race and is setting the agenda for the party. She took in the glare for the largest share of the three-hour debate without wilting, or receding for significant chunks of the evening (as she did in previous encounters) when the issues shifted away from terrain where she is most comfortable.

The second dynamic was an honest illumination of the party’s left-vs.-center debate. In past encounters, this conversation often was portrayed as a choice between “activists” and “establishment,” or between bold principles and expedient moderation.

Thanks in part to articulate and forceful performances by Sen. Amy Klobuchar and Mayor Pete Buttigieg, the centrist case on specific issues like health care and gun control, and broader ones like how to drive change in an era of relentless partisanship, were made more robustly and with less defensiveness than in the past.

The choice before Democrats was laid out in plain and unpretentious style.

People like Warren and Sen. Bernie Sanders (whose pitch and style never seems to change much, even after a recent heart attack) believe the way to earn credibility with disillusioned voters and beat President Donald Trump is by advocating big plans that fundamentally challenge power structures in Washington and in corporate America. Biden, Buttigieg, Klobuchar, Sen. Cory Booker and others argued that the way to earn credibility and beat Trump is by building a consensus for progressive ideas that have near-term prospects actually to be enacted.

That is by no means a new argument for Democrats, but it was engaged Tuesday in a more authentic fashion. In contrasts to early debates, the candidates whose careers have been marked by centrist impulses didn’t tip-toe around their views, or alter their substantive and rhetorical pitches to project more radical personas. The debate wasn’t defined by dramatic contrivances, such as last summer’s debate when Sen. Kamala Harris attacked Biden on his busing record 45 years ago, even though support for busing has never been a pillar of her own record and she had earlier been a Biden ally.

The essential sincerity of the debate, which was held at Otterbein University in suburban Columbus, flowed in both directions.

Warren became animated when she defended herself against former Rep. Beto O’Rourke’s suggestion that her anti-business views come off “more about being punitive and pitting some part of the country against each other, instead of lifting people up.” Along the way, she seemed to forecast her likely response to the same charge in the general election should she become the Democratic nominee.

“So I'm really shocked at the notion that anyone thinks I'm punitive,” Warren said. “Look, I don't have a beef with billionaires. My problem is you made a fortune in America, you had a great idea, you got out there and worked for it, good for you. But you built that fortune in America. I guarantee you built it in part using workers all of us helped pay to educate. You built it in part getting your goods to markets on roads and bridges all of us helped pay for. You built it at least in part protected by police and firefighters all of us help pay the salaries for.”

On her general philosophy of change, she cited her experience after the 2008 financial crash successfully promoting enactment of a new agency to protect consumers. She ignored advice from people who told her, Warren said, that she was more likely to win if she would “go for something small, go for something the big companies will be able to accept.”

Sanders struck many of the same themes: “The way you win an election in this time in history is not the same old same old. You have to inspire people. You have to excite people. You've got to bring working people and young people and poor people into the political process.”

But others disputed the idea that the way to bring change is by pushing for the most dramatic version of change, as quickly as possible, or by dismissing those who disagree as weaklings or appeasers.

On the familiar question of whether Democrats should try to expand Barack Obama’s Affordable Care Act or scrap it in favor of mandatory “Medicare for All,” Klobuchar defended the more incremental approach. “I’m tired of hearing whenever I say these things, ‘It’s Republican talking points,’ she said. "I appreciate Elizabeth’s work [but] the difference between a plan and a pipe dream is something that you can actually get done.”

On the question of imposing a “wealth tax” on big fortunes, Buttigieg professed he is “all for” it and other ideas he heard from debate rivals. “Let me tell you, though, how this looks from the industrial Midwest where I live,” he said. “Washington politicians, congressmen and senators, saying all the right things, offering the most elegant policy prescriptions, and nothing changes.”

Praising Warren’s vision, but criticizing her vagueness about how to pay for Medicare for All, Biden said, “We've got to level with people. We've got to level with people and tell them exactly what we're going to do, how we're going to get it done, and if you can get it done.”

While candidates highlighted differences without artifice, they also showed heightened command of policy even on places where they were in agreement, or the variances of their positions were matters of degree rather than a deeper philosophical conflict. Everyone supported impeachment proceedings against Trump, though with varying degrees of caution about the need to follow due process or elicit a modicum of bipartisan support. (This was the first debate for billionaire Tom Steyer, an outspoken impeachment advocate).

Everyone denounced Trump for betraying Kurdish allies by precipitously pulling a contingent of U.S. troops out of Syria and allowing a Turkish incursion, though Rep. Tulsi Gabbard launched a broader critique of a U.S. “regime change war” that she said had begun under Obama, drawing a sharp response from Buttigieg.

Everyone supported getting tougher with regulations on big tech companies, though businessman Andrew Yang said Warren is too simplistic in thinking breaking up the firms can solve more systemic challenges, like the disruption to workers from artificial intelligence.

Everyone supported stricter gun controls, but Julián Castro expressed skepticism of mandatory buybacks of assault weapons in distinctly personal terms when he said, "In the places I grew up in, we weren't exactly looking for another reason for cops to come banging on the door."

What’s more, no one could claim that the format left no time for nuance or elaboration. Earlier debates were marked by shouts from candidates of “Let me finish!” In this case, some of the protests surely came at home from viewers, “When will this finish?”