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The NewsHour is hosting the next Democratic debate on Thursday. You can find live coverage and all kinds of related materials on our website. 

WHAT TO EXPECT AT THE SIXTH DEMOCRATIC DEBATE
By Daniel Bush, @DanielBush
Senior Reporter, Digital Politics

Seven candidates will appear at the sixth Democratic debate Thursday in Los Angeles: Former Vice President Joe Biden, South Bend Mayor Pete Buttigieg, Senators Elizabeth Warren, Bernie Sanders and Amy Klobuchar, entrepreneur Andrew Yang, and the billionaire environmental advocate, Tom Steyer.

The PBS NewsHour/POLITICO debate comes as the impeachment battle in Congress is coming to a head -- and in a moment when the primary field remains unsettled with less than two months to go before voting begins. Here’s a guide of things to watch for Thursday. (Click here for a full preview of the debate).

Pete Buttigieg in the spotlight

The mayor of South Bend, Indiana has taken off in the polls since the last debate in November. Now he’ll take the debate stage in Los Angeles as one of the frontrunners for the first time this primary season, which will come with added scrutiny that often trips up leading candidates. 

Buttigieg, who is 37 years old, has found success on the campaign trail and in debates by focusing on his vision for moving the country forward. To succeed Thursday, he’ll need to stick to that message and demonstrate why he’s qualified for the most powerful job in the world.

Can Warren regain momentum?

For a few months in the late summer and early fall, Warren shot up in the polls as voters gravitated to her policy-driven, selfie line-powered campaign. But then she unveiled a “Medicare for All” proposal that angered progressives and moderate Democrats alike. After that, Warren quickly lost momentum, and along with it, her one-time frontrunner status. The debate Thursday is a chance for Warren to get back on track. On the progressive front, Warren will need to re-energize the party’s liberal base. On the other end of the spectrum, Warren must convince moderate Democrats that she has the best chance to beat Trump next November. Warren successfully threaded that needle in previous debates, and will be under pressure to do so again Thursday.

Will Biden (finally) deliver a standout debate performance? 

So far, Biden has not been at his best in the Democratic primary debates. And yet, his debate struggles haven’t hurt him substantially; Biden remains on top in national polls and in South Carolina and Nevada, two key early voting states. At the same time, the fact that Biden has struggled in the debates has left the door wide open for others to challenge him, raising questions about whether he can take on Trump in 2020. Biden could lay some of the criticism to rest with a strong debate in Los Angeles. 

Sanders is bouncing back

Sanders was largely written off by detractors and political pundits after suffering a heart attack in early October. The health scare raised questions about his age -- at 78 years old, Sanders is the oldest candidate in the race -- at a time when he was sinking in the polls. But Sanders bounced back and enters Thursday’s debate with more momentum than he’s had in months. 

Still, Sanders still faces the same obstacles he did at the start of the primaries. He’s viewed as too liberal by many moderate Democratic primary voters, and his age and health remain a concern for some voters. Despite these challenges, Sanders has refused to adjust his campaign -- and his supporters and online donors deeply admire his conviction. But so far his refusal to waver hasn’t been enough to put him atop the polls.

Lower-tier candidates have a big opportunity on a smaller debate stage

The debate stage will be smaller because fewer candidates met the higher thresholds of polling and fundraising needed to qualify. The format will shine a brighter spotlight on the candidates who are not in the top tier. For Yang and Steyer, who are both first-time candidates, the debate will be the most high-profile moment of their political careers. 

Thursday’s debate will also have some conspicuous absences, leading to a lack of diversity. Sen. Cory Booker won’t be on the debate stage, though he has shown no signs of dropping out of the race. Sen. Kamala Harris ended her White House bid earlier this month. They were both seen as strong contenders when they launched their campaigns. 

FIVE OVERLOOKED POLITICAL STORIES FROM THE PAST WEEK

By  Alex D’Elia, @AlexDEliaNews
Politics production assistant

Judge orders state to purge more than 200,000 Wisconsin voters from the rolls -- Dec. 13. A judge said hundreds of thousands of voters who may have moved should be removed from the rolls. Activists are racing to get voters reregistered. Why it matters: Ballot access has been a key issue in recent elections, with Democrats accusing Republicans of trying to limit access for poor and minority voters. -- Milwaukee Journal Sentinel

Army, Navy officials investigate possible ‘white power’ gestures by students -- Dec. 16. Students at the service academies appeared to use a hand gesture that has been associated with “white power” on television before the annual football game between the two schools. Why it matters: Organizations that monitor hate groups have called the gesture a hate symbol. The schools have said only that they are investigating the incident. -- The Washington Post

Top Democratic candidates ask DNC to change debate qualifying rules -- Dec. 14. Nine candidates who did not make the debate stage have asked the Democratic National Committee to change the rules for upcoming debates to ensure a more diverse pool of candidates. Why it matters: Six of the seven candidates on the stage for the next debate, which is set for Thursday, are white, leading to charges that the DNC rules are denying the national exposure to a historically diverse set of candidates. -- NBC News

Hundreds of historians speak out on impeachment -- Dec. 16. More than 750 historians from across the country have signed a letter expressing their support for the impeachment of President Trump.  Why it matters: It is unlikely academics will sway Republican lawmakers who have not wavered in their support for the president. -- The New York Times

NJ Senate cancels vote on controversial vaccination bill after hours of protests -- Dec. 16. The state was poised to pass a ban on religious exemptions for vaccines when the vote was canceled after noisy protests. Why it matters: Health officials fear that religious exemptions from mandatory vaccines is decreasing the number of vaccinated children below the threshold needed to protect vulnerable populations. -- POLITICO

#POLITICSTRIVIA
By Kate Grumke, @KGrumke
Politics producer

Here at NewsHour, we're gearing up to host the Democratic debate on Thursday. In that spirit, here's some debate trivia we learned while preparing.  The first televised presidential debate in U.S. history was between John F. Kennedy and Richard Nixon in 1960. Many things were different back then, but a big one was the pace of the debate compared to today. For example, there were no time limits for the candidates' responses.

Our question: What was the time limit for their opening statements? 

Send your answers to [email protected] or tweet using #PoliticsTrivia. The first correct answers will earn a shout-out next week.

Last week, we asked: How many presidents and vice presidents have won a Nobel prize?

Answer: Six (four presidents and two vice presidents) 

Congratulations to our winners: J. Brydon!

Thank you all for reading and watching. We’ll drop into your Inbox next week.