As Democrats get ready for their first debate with all qualifying candidates on a single stage, the crowded 2020 Democratic nomination battle is believed by many to be a three person race: Joe Biden, Sen. Elizabeth Warren, and Sen. Bernie Sanders. But with nearly five months to go before the first votes are cast in Iowa, there’s still a good chance that at least one of the candidates currently in the lower-tier will break out and vault into the top-tier. Thursday night’s debate could provide the best opportunity for the other seven candidates on stage to do so. So what’s the best chance for the non-Biden-Warren-Sanders candidates to break out? Let’s look at them one by one.

Sen. Kamala Harris

Going in to the primaries, Harris was seen by many insiders as the true front-runner. This was partially due to shortsighted assumptions about the way identity politics functions electorally. That is, there were those who felt that because she was both black and female, she could appeal to multiple key Democratic constituencies. Furthermore, others felt that by being ideologically malleable, she was well-positioned to satisfy the Left of the party without scaring off establishment liberals. As a bonus, the decision of her home state of California to move up its primary, with it’s massive delegate haul, was seen to benefit her greatly. The problem is that you cannot face-plant early and hope to be bailed out in your home state. If Harris doesn’t turn things around and come out of the early states in the top-tier, she won’t be saved by California, which awards delegates proportionally at the state and congressional district level. Harris has shown flashes of the political skills that made so many experts pick her as the most likely nominee. She had a smooth rollout of her campaign, and a dominant performance in the first debate. But whenever the campaign retreated to the day-to-day, she’s faded, and now finds herself out of the top-tier. In the first debate, Harris showed how she was able to knife Biden, but she stumbled in the days and weeks that followed as she backed off and “clarified” positions taken during that debate. On Thursday, Harris may want to take a step back from hammering other candidates in the field, and as they fight amongst themselves, focus on what she claims is the main case for her candidacy — prosecuting the case against President Trump.

Pete Buttigieg

The small-town mayor and fundraising juggernaut made a surprising splash early on in the presidential race, but hit a ceiling, and has failed to prove that he has a second act beyond being a likable and smart young Democrat. His abysmal polling among black voters will block his road to the nomination, but his pile of cash should allow him to compete in Iowa, and if he does well there, in New Hampshire. At this point, it’s difficult to see how exactly he leapfrogs the other candidates in Iowa, but it would not be unheard of for a candidate to surge late in the state. So any message he has on Thursday should clearly be tailored with the Iowa electorate in mind.

Sen. Amy Klobuchar

A favorite of many pundits who are hoping for a more traditional liberal nominee, the low-key Klobuchar has had difficulty getting any attention in a crowded field in which Biden is dominating among the center-left. The clearest path to relevance for Klobuchar is to position herself as the most viable choice for those who are worried about the party becoming too radical. As a representative of a neighboring state, Iowa could in theory, be open to her message. As long as Biden is up top, it’s difficult to see much of a path for her. But she could use Thursday’s debate as a chance to position herself in a way so that she would benefit from any collapse in support for Biden.

Sen. Cory Booker

Looking ahead to the 2020 election a few years ago, Booker was seen as a leading contender. But as a candidate, he has failed to gain traction. As mayor of Newark and early in his Senate career, Booker positioned himself as somebody in the center-left who could work with Republicans on certain areas of agreement. Since then, however, he’s tried, ineffectively, to chase the left-throng of the party and to present himself as more of a bomb thrower. He now finds himself in a political no man’s land with no clear path to the nomination. Even a well-reviewed performance in the second debate didn’t do much for him. Like Klobuchar, he may need somebody else to falter to get a serious look from voters.

Beto O’Rourke

It’s difficult to see his candidacy going anywhere. It’s one thing to poll modestly early and surge late. It’s another to be hailed as a rising star, vault toward the top-tier, collapse as people realize there isn’t much there, and then think you’ll be able to recover. O’Rourke has resorted to dropping F-bombs and calling for mass gun confiscation, but that is more likely to make him look desperate than to improve his odds. Expect more wild statements from O’Rourke on Thursday night, likely to no avail. At this point, the question isn’t even whether he can make a play for the nomination, but whether he can come out of this race with any semblance of a political career.

Andrew Yang

In a crowded field, Yang has done an impressive job of getting attention. Even those who don’t have much intention of voting for him are, by now, likely familiar with his warnings about automation and his plan to provide a universal income of $1,000 per month. The challenge for him on Thursday is to take the platform he’s earned and explain to voters why they should want him as their president, rather than just as a messenger.

Julián Castro

Castro has spoken passionately, particularly on immigration, even when it has meant blistering criticism of the Obama administration. The problem he faces is that save Nevada, he doesn’t have any clear opening in any of the early states, and will have a difficult time sustaining his campaign until the nomination battle comes to Texas, where he isn’t even polling well anyway. At this point, Castro’s debate may be more of an audition to be somebody’s running mate will be the start of his surge toward the top-tier.