The first night of the first debate is in the books, and you can read all about it here.

Here’s what to look for on the second night.

A trying moment for Biden

The leading candidate in early polling in Wednesday night’s event, Sen. Elizabeth Warren (Mass.), largely got a pass from her competitors, even as they were invited, right from the jump, to differ with some of her most liberal policy proposals. It turned out the other candidates were much more willing to fight with one another, with even the two Texans and the 1-percenters mixing it up with one another.

The leading candidate in Thursday night’s event, Joe Biden, is unlikely to get such a glide path. Sen. Bernie Sanders (I-Vt.) has shown an appetite to attack him from the left — though he hasn’t always gone for the jugular — and other candidates have had tough words as well. Biden has also walked himself into some controversies, most recently by hailing his relationships with segregationist senators, that should invite some spirited debate.

Thursday night will also be a test for Biden, who as a candidate hasn’t really answered questions at length or made a ton of public appearances. He also got a later start than most any other candidate. He’s never been in this position in his previous presidential campaigns. And his message discipline isn’t always the best. Needless to say, there are a lot of questions about Biden that could be answered Thursday.

Kamala D. Harris’s prosecutorial moment

The Biden vs. Sanders matchup got all the publicity immediately after the debate lineups were announced a couple weeks ago. But the third-leading candidate in the race, Sen. Kamala D. Harris (Calif.), has a real chance to make some important first impressions.

And not only that, but Harris has suggested her past as a prosecutor would make her an ideal foil for Trump. “We need somebody on our stage, when it comes time for that general election, who knows how to recognize a rap sheet when they see it and prosecute the case,” she said recently in South Carolina.

Given that kind of talk, the onus is on Harris to back it up with a strong performance and show that she is the debater and prosecutor she claims to be.

Buttigieg’s delicate balance

South Bend, Ind. Mayor Pete Buttigieg has been one of two momentum candidates early in the race, along with Warren. But this debate comes at a trying time, as he seeks to manage a hometown that is on edge after the recent shooting death of a black man by a police officer. Buttigieg temporarily suspended his campaign, but he opted to show up for Thursday’s debate.

Setting aside the very important and sensitive issues involved, on a purely political level, this is an important moment for Buttigieg. Much like former congressman Beto O’Rourke, he has to combat the perception that he’s a young and perhaps inspiring candidate, but that he may not be presidential timbre or the kind of leader these times call for. Reporting has pointed to some reservations about his tenure in South Bend, including from the poor and African Americans.

There is a reason we have few former mayors who became president; it’s a job that carries lots of accountability. Buttigieg is dealing with that back home; now he deals with it on his first big, national debate stage.

The wild cards

Thursday night’s debate will feature some truly little-known hopefuls who managed to make the debate stage: author Marianne Williamson and businessman Andrew Yang. Both have run into controversy, including Williamson recently with her comments about vaccines (which she backed off from but not completely) and Yang for his brief venture into circumcision politics. But Yang, in particular, has managed to grow a genuine and passionate following, including by pushing for universal basic income. All of these things could provide some unique dynamics Thursday.

Also keep an eye on former Colorado governor John Hickenlooper (who managed to convince the venue in Miami that he’s a candidate and not another slovenly journalist). He has shown perhaps the most willingness to go after Sanders on democratic socialism, and you can bet he’s got that teed up for the debate. And two senators struggling for traction — Kirsten Gillibrand (N.Y.) and Michael F. Bennet (Colo.) — will have a chance to make first impressions, along with Rep. Eric Swalwell (Calif.).