Who knew picking 20 names out of a box could be so entertaining? In a live draw held on Thursday, CNN selected the lineups for the second Democratic presidential primary debate. Former Vice President Joe Biden and Sen. Kamala Harris are set for a rematch while Sens. Bernie Sanders and Elizabeth Warren, the leading progressive candidates, face not only a potential clash with each other, but also with more moderate members of the party.

To set each night’s stage, CNN created three groups of candidates based on polling since the first debate, with each night getting five of the 10 candidates polling below 1 percent, three of the six candidates polling between 1 and 10 percent, and then two of the four leading candidates polling above 10 percent. While the draw for the first debate resulted in a lopsided set of candidate lineups, this time around the two nights will be fairly even.

No undercard this time Combined polling averages of the candidates for each night of the second 2019 Democratic debate July 30 debate Avg July 31 debate Avg Bernie Sanders 15.1 – Joe Biden 25.5 Elizabeth Warren 13.1 – Kamala Harris 13.5 Pete Buttigieg 5.0 – Cory Booker 2.0 Beto O’Rourke 1.8 – Andrew Yang 1.3 Amy Klobuchar 1.0 – Julián Castro 1.1 Marianne Williamson 0.5 – Tulsi Gabbard 0.6 John Delaney 0.5 – Michael Bennet 0.5 John Hickenlooper 0.3 – Jay Inslee 0.3 Tim Ryan 0.1 – Kirsten Gillibrand 0.3 Steve Bullock 0.1 – Bill de Blasio 0.1 Total support 37.5 – Total support 45.2 Average support 3.75 – Average support 4.52 Candidate averages based on the eight debate-qualifying polls that have been released since the first debate. Total support does not add up to 100 percent due to undecided respondents, support for candidates who are no longer running for president and support for candidates who didn’t qualify. Source: Polls

Undoubtedly, a major storyline will be Biden and Harris facing off again after the fireworks in the first debate, when Harris criticized Biden for having worked with segregationist senators and opposing school integration via busing in the 1970s. How Biden and Harris fare this time could be meaningful for support among black voters. African American voters have largely stuck with Biden, but Harris has attracted more support since the two candidates first clashed, and she now leads in endorsements from the Congressional Black Caucus.

It will also be interesting to see how Sanders and Warren square off, especially now that their rumored nonaggression pact might no longer exist. Sanders and Warren occupy the same “lane” within the party, so their presence on the same stage gives each the chance to differentiate their progressive visions for the country. That said, their supporters actually don’t have that much in common (Sanders backers view Biden as their preferred second-choice candidate while Warren supporters prefer Harris).

At least two other matchups merit watching. South Bend, Indiana, Mayor Pete Buttigieg and former Rep. Beto O’Rourke both debate on the first night, and because Buttigieg’s rise earlier this year may have stifled O’Rourke’s candidacy, how they compete for some of the same voters could be telling. Meanwhile, although Harris and Biden had a big moment in the first debate, this time Sen. Cory Booker also gets his chance to take a shot at Biden after criticizing the former vice president for his comments about “civility” and working with segregationist senators.

Although the draw (successfully) avoided having too many top-tier candidates on the same night, the randomness of the draw did lead to some imbalances. Notably, July 30 will feature only white candidates while all the nonwhite candidates take the stage July 31. Additionally, most of the relatively moderate candidates ended up on the first night — though they’ll be joined by Sanders and Warren. This could provide an opportunity for the moderate candidates to gang up on the two left-wingers, particularly on an issue like health care. By the same token, Biden could be a target on the second night for being too moderate.

This will also be the final opportunity for many of the low-polling candidates in the race to break out. Thus far, only six candidates have qualified for the third debate, and it’s hard to see too many more making it with the higher polling and donor requirements for qualification. So we shouldn’t be too surprised if lower-tier candidates act more aggressively — or desperately — to make a splash and go viral to stay relevant in the Democratic primary, lest they suffer the fate of Eric Swalwell.