The second night of the July Democratic debates featured a rematch between former Vice President Joe Biden and Sen. Kamala D. Harris of California, who clashed in last month’s debate. Sen. Cory Booker of New Jersey, who has sparred with Biden in recent days, joined them with the expectation that he could challenge one or both on criminal justice policies.

So how’d the candidates do Wednesday night? Here’s your chance to weigh in. When all was said and done, who bested whom? Scroll down to register your vote.

CNN hosted and broadcast the two hour event. CNN journalists Dana Bash, Don Lemon and Jake Tapper served as moderators.

Unlike the previous set of debates held in June, the rules stipulated that there will be no questions requiring a show of hands from the candidates. Frequent interruptions by a particular candidate would result in reduced time for that candidate to speak on other occasions. Candidates received 60 seconds to respond to questions and 30 seconds for rebuttals.

Here’s a complete list of the candidates who debated Wednesday, in alphabetical order:

Sen. Michael Bennet of Colorado; Biden; Booker; former Housing Secretary Julián Castro; New York City Mayor Bill de Blasio; Rep. Tulsi Gabbard of Hawaii; Sen. Kirsten Gillibrand of New York; Harris; Washington Gov. Jay Inslee; and businessman Andrew Yang.

The following candidates debated on Tuesday: Montana Gov. Steve Bullock; South Bend, Indiana, Mayor Pete Buttigieg; former Maryland Rep. John Delaney; former Colorado Gov. John Hickenlooper; Sen. Amy Klobuchar of Minnesota; former Texas Rep. Beto O’Rourke; Rep. Tim Ryan of Ohio; Sen. Bernie Sanders, I-Vt.; Sen. Elizabeth Warren of Massachusetts; and author Marianne Williamson.

[Who won Tuesday night’s Democratic presidential debate? Vote here.]

Biden, having concluded he was not aggressive enough in the first clash in June, has practiced criticizing his rivals on health care and other issues as he prepared for round two.

After he was pummeled in the last debate by Harris and others, Biden has shifted most dramatically between the televised sessions. The candidate who three weeks ago said he saw no reason to dig into the past records of his opponents has been doing just that. The candidate who once warned against a “circular firing squad” is now joining the circle.

Bakari Sellers, a former South Carolina legislator who supports Harris, was among those arguing that Biden is the candidate under the most pressure to perform well.

[Polling shows ‘5-person race’ for the 2020 nomination]

"He can't display a glass jaw in back-to-back debates," said Sellers. "If he does that, his support will creep away."

Onstage Wednesday night, Biden stood between Harris and Booker, who have been critical of Biden’s record and prepared for volatile and personal exchanges. On Tuesday, the center stage was held by the liberal pairing of Sanders, who came in second in the 2016 Democratic contest but has lost ground of late, and Warren, who has overtaken him in some polls.

The two-day period represents the next crossroads in the Democratic contest, and for some candidates, it could also be their last stand. More than half of the field is at risk of falling short of the polling and donor thresholds needed to appear in the third debate in September, making this week perhaps their final opportunity to shake things up.

That has given even more emphasis to the lesson learned in June: On such a crowded stage, it pays to break the rules. Interrupt if you have to, talk longer than the allotted minute if you must, and above all, seek a controversy-stirring moment that cable television will play for days afterward.

That was the preplanned recipe Harris followed in the last debate. The result of her June joust with Biden was she, more than any of the 20 candidates onstage, leaped in the rankings. She also got a fundraising boost from the sale of a T-shirt that played off her key moment, when she contrasted Biden's opposition to busing for integration with her experience as a child bused to school.

Some candidates are preparing less on how to deliver their own lines than on how best to interrupt their opponents.

"One of the things that we learned is that it is a total free-for-all. It was like a children's soccer game, 10 candidates swarming the ball," said a senior adviser to one of the candidates, who, like many interviewed, requested anonymity to discuss internal deliberations. "We have done a lot less practice of what your 60-second answer is and a lot more practice of live fire drills of how to interject into the debate."

Biden's new posture has been evident since the day after the last debate, when he defended his past civil rights record more definitively than he had onstage the night before. Biden would generally brush aside opportunities to criticize any of his opponents, focusing almost exclusively on President Trump.

"I get all this information about other people's pasts, and what they've done and not done - and, you know, I'm just not going to go there," Biden told CNN. "If we keep doing that - I mean, we should be debating what we do from here."

He has since sharpened his attacks on Sanders for his signature health care plan, which he has said would raise taxes on the middle class even as it lowered health-care costs. He has also recently called the notion that young voters want revolutionary change "fiction" and declared, "They aren't a generation of socialists" - a seeming reference to Sanders' brand of democratic socialism.

Over the past week, with his own record under scrutiny, Biden began criticizing Booker's backing of the police department's "stop and frisk" policy while he was mayor of Newark with such ferocity that Booker's campaign was taken aback. Biden also took issue with Harris after she said she did not support a middle-class tax hike to pay for the Medicare-for-all plan she endorsed; only in "a fantasy world" would the tax hike not be necessary, he said.

Biden said he felt like a target going into the second debate. "As long as you're leading, you're the target." He added, "I'm looking forward to it."

Biden’s campaign has been bracing for attacks from multiple candidates beyond Harris and Booker, with critiques on his record on trade and workers’ rights from New York Mayor Bill de Blasio, on women’s and abortion rights from Gillibrand and on immigration policy from Castro.

"Everyone is looking for their T-shirt moment," said one Biden campaign official. "And Joe Biden thinks this is bigger than selling T-shirts."

Biden's campaign advisers think they could benefit most from a debate over health care. He has argued strenuously for expanding Obamacare rather than establishing a government-run system.

The two biggest proponents of Medicare-for-all - Sanders and Warren - were not on the stage with him, but Booker, Harris and Gillibrand, who are co-sponsors of the legislation, were. Harris in particular has stumbled in the past over how far she would go in ending the private insurance system.

Harris has largely ignored her opponents lately, although she has sought to distinguish herself from them in key ways. Some Harris allies don't expect her to be looking for a fight.

"I kind of expect Senator Harris to take a more presidential approach to the debate and only smack when being attacked - which may be frequently," Sellers said.

[What you need to know about the Democratic debates]

The Washington Post’s Michael Scherer and Annie Linskey contributed to this report.