How to watch -- and what to watch for -- in tonight's Democratic presidential debate
The first official Democratic presidential primary debate is a big deal for the 20 candidates who qualified to be on the debate stage.
"You get one chance to make a good first impression," said Democratic strategist Mary Ann Walsh.
The debates begin at 8 p.m. and Thursday on NBC, MSNBC and Telemundo.
Why are there two nights? Because so many candidates qualified for the debate thresholds, the Democratic National Committee split them into two groups, with 10 candidates each night.
Most candidates are randomly selected for each night, but the DNC spread out the top-polling candidates between the two stages.
Here are some things to watch for.
1. Is anyone going to have a breakout moment?
The debate will be unruly, with 20 candidates and five moderators spread over two nights. The current leaders in the polls aren't even on the same stage.
The closest precedent to this is the early 2016 Republican primary debates, in which the Top 10 candidates were invited to a main debate and there was an "undercard" debate earlier in the day.
There was a lot of back-and-forth, even some shouting. In the end, one person dominated -- and that person is now president.
2. Does Joe Biden engage with the other candidates?
The former vice president has been running his race as if he's already the nominee.
He's leading in every major poll. But for at least one night, he'll be sucked back into the primary for this debate, with a target on his back. Speaking of ...
3. How does everyone else go after Biden?
One good way to get yourself heard is to draw a contrast with Biden -- maybe even draw blood from him, says Walsh.
But so far, most candidates have avoided directly criticizing Biden, and certainly not by name. Does that change in the first debate?
"At some point, the debate is going to get much sharper," said Democratic strategist Jim Manley. Going after the leader in the polls is simply what one has to do to get noticed.
4. How do all the women onstage change the dynamic?
This field is one of the most diverse in history. Six of the 20 candidates in the debate will be women, a first for any major party.
Do they talk about their gender, even own it, in a way female politicians haven't in the past?
How could their presence trip up any of the men or moderators?
5. How do the most successful candidates contrast themselves with Trump?
Who's most electable against Trump is a thick undercurrent in the Democratic primary.
"Electability" is a subjective (and at times, gender-biased) term that voters are wrestling with. To that end, every candidate is going to want voters to imagine they're debating Trump -- not other Democrats -- onstage.
There's no consensus on how to successfully do that. Biden is already talking about Trump by name more than most candidates, but does he get in a back-and-forth with Trump, via social media or cable news?
Does he respond to Trump calling him "the weakest mentally," for example?
Do the candidates try to focus heavily on policy rather than personality and just ignore Trump? Some candidates are signing onto a pledge not to use stolen information in their campaigns, for example. And how does all of this play into the broader Democratic debate about how antagonistic to be toward Republicans?
6. How many times is "socialist" mentioned?
Another defining debate of the Democratic Party is whether it's moving too far left (by proposing government-run policies like Medicare-for-all), or whether that's exactly what needs to happen to beat Trump.
Jim Kessler, a Democratic strategist with the centrist Third Way think tank, suggested keeping an eye on whether candidates use the term as an epithet or a point of pride.
7. How negative does Bernie Sanders go?
A couple of strategists mentioned to me that if any candidate is going to take his or her gloves off, it's likely to be Sanders.
He is not a conciliatory politician by nature. He's already gone after Biden. But we might see Sanders on the defensive, too.
In the 2016 primary, Hillary Clinton largely avoided attacking him. Given he's second, behind Biden, in many polls, we could witness Sanders on the defensive for the first time.
Wednesday's debate will feature: New York Mayor Bill de Blasio, Sen. Cory Booker of New Jersey, former Obama Cabinet member Julián Castro, former congressman John Delaney of Maryland, Rep. Tulsi Gabbard of Hawaii, Washington Gov. Jay Inslee, Sen. Amy Klobuchar of Minnesota, former congressman Beto O'Rourke of Texas, Rep. Tim Ryan of Ohio and Sen. Elizabeth Warren of Massachusetts.
Thursday's debate will feature: Former vice president Joe Biden, Sen. Bernie Sanders of Vermont, Sen. Kamala Harris of California, Sen. Michael Bennet of Colorado, Mayor Pete Buttigieg of South Bend, Indiana; Sen. Kirsten Gillibrand of New York, former Colorado governor John Hickenlooper, Rep. Eric Swalwell of California, author and spiritual guru Marianne Williamson and technology entrepreneur Andrew Yang.
The moderators are "Today" co-anchor Savannah Guthrie, "NBC Nightly News" anchor Lester Holt, "Meet the Press" moderator Chuck Todd, "The Rachel Maddow Show" host Rachel Maddow and "Noticias Telemundo" anchor José Diaz-Balart.
Date: Wednesday, June 26, and Thursday, June 27
Time: 8 p.m. to 10 p.m.
Where: NBC, MSNBC and Telemundo