Breakouts and death knells: Here's what to expect at Tuesday night's Democratic primary debate

At 8 pm ET on Tuesday night, ten of the Democratic presidential candidates will face off on CNN the first round of the second debate. The candidates taking the stage are Sens. Elizabeth Warren (D-MA), Amy Klobuchar (D-MN), and Bernie Sanders (I-VT), Reps. Beto O'Rourke (D-TX), Tim Ryan (D-OH), and John Delaney (D-MD), Govs. Steve Bullock (D-MT) and John Hickenlooper (D-CO), South Bend Mayor Pete Buttigieg, and self-help author Marianne Williamson.

Ahead of the debate, Chuck Todd, Mark Murray and Carrie Dann wrote an analysis for NBC News walking though some of what viewers can expect from the night.

To begin with, they noted, Sanders and Warren are likely to show off their progressive bona fides to stand apart from the more moderate candidates like Klobuchar, Hickenlooper, and Delaney, which could set up clashes between these two groups. There is likely to be a spirited debate about who is "electable" and whether that even should be considered something distinct from their policymaking skill, and over the generation gap between many of the candidates, from 37-year-old Buttigieg to 77-year-old Sanders.

One dynamic they say is a mystery will be who Sanders goes up against. His campaign has sought to challenge former Vice President Joe Biden and Sen. Kamala Harris (D-CA) on health care, but neither will be on the stage. Klobuchar, however, has expressed a health care proposal similar to Biden's, so it may be her that he turns the focus on.

Another wildcard is Bullock, who did not qualify for the first debate and will be on the national stage for the first time. As a successful red state governor, he is a powerful candidate on paper, but he has yet to play a major role in the primary, and tonight could be a breakout moment.

Lastly, they noted, viewers should pay attention to the people polling under 1 percent — as this debate could either vault them into a higher tier or prove the death blow for their campaign.