By Mark Z. Barabak

Los Angeles Times

It’s mid-September, a time when the days grow shorter, the leaves begin to fall and all across the land thoughts turn to … well, not to presidential politics.

Even so, 10 Democrats clamoring to win the White House in 2020 will return to the debate stage Thursday night for three hours of questions and answers, elbows and jockeying, and all the carefully scripted spontaneity the candidates can muster.

The number is down from the 20 contestants who participated in the first and second round of debates, which were split over two nights in June and again in July.

Still, the format will be familiar to any who tuned in for those broadcasts; the forum is not so much a debate but an opportunity for voters to see the candidates answer a series of questions and react to their rivals while standing side by side.

ABC is putting on the show, telecast from Houston, along with the Spanish-language station Univision.

Q. What time is the debate?

A. It begins at 5 p.m. Pacific time.

Q. Why was the field cut in half? A virulent flu that struck the politically ambitious?

A. Um, no.

Invitations were extended only to those who met requirements established by the Democratic National Committee. The criteria were tightened to make it harder to reach the debate stage.

Q. How so?

A. Initially candidates had to meet one of two benchmarks: appeal to 65,000 donors, with at least 200 coming from 20 different states; or receive 1% or more support in three state or national polls sanctioned by the DNC.

That changed for September’s matchup.

The candidates had to register support of 2% or better in at least four polls and have at least 130,000 donors, including a minimum of 400 unique donors in each of at least 20 states.

Q. 2%? You would think staffers and blood relatives would qualify a candidate!

A. Apparently not.

Q. So who’s in?

A. In alphabetical order: former Vice President Joe Biden; New Jersey Sen. Cory Booker; South Bend, Ind., Mayor Pete Buttigieg; former Housing Secretary Julian Castro; California Sen. Kamala Harris; Minnesota Sen. Amy Klobuchar; former Texas Rep. Beto O’Rourke; Vermont Sen. Bernie Sanders; Massachusetts Sen. Elizabeth Warren and entrepreneur Andrew Yang.

Q. Apart from fewer candidates, what’s different this time?

A. Perhaps the most significant change is that all of the top-tier candidates will be together onstage for the first time, rather than sprinkled over two nights.

Q. Intriguing!

A. The dynamic between Biden and Warren will be particularly interesting, given not just their proximity in polls but the fact they embody the philosophical divide in the race, between the relative centrism of the former vice president and the leftward leaning of Warren.

The two have a long, somewhat adversarial history, and if they chose not to engage, you can be pretty certain the debate moderators will seek to draw out their distinctions on healthcare and a past run-in over regulating the credit card industry, among other differences.

Q. Any other subplots?

A. Harris was the standout on June’s debate stage and was widely panned for her performance in July. She badly needs another strong showing to break out of her campaign doldrums.

O’Rourke, meantime, has been lackluster in previous debates, falling well short of his electric performance on the campaign trail. He’s chucked the conventional political playbook to turn his candidacy into a fiery crusade against President Trump and in, particular, in favor of stricter gun controls. Will he be more of a factor in Thursday night’s debate?

Q. Anything else?

A. Do you enjoy reruns?

Q. Sometimes.

A. Warren and Sanders are personal friends and political allies. They made nice on the debate stage in July. The question, again, is whether they end their entente as they seek to broaden their appeal to the same set of political-revolution-minded voters.

And then there’s the perennial question of what, if anything, the rest of the candidates can do to break from the pack and launch themselves into the campaign’s top tier.

Q. How can I watch the debate?

A. In addition to the broadcasts on ABC and Univision, various services will be streaming the session, including AppleTV and YouTube.

Q. I kind of liked when there were more candidates than people in the audience.

A. That’s an exaggeration, but take heart. The field will expand again for round 4 next month in Ohio.

Q. Oh?

A. San Francisco billionaire Tom Steyer, who fell just shy of qualifying this time, made the cut for the next debate, and there’s still time for others to make the stage.

Q. Woo-hoo!

A. But don’t count on 20 candidates showing up. Several who were on hand in June and July, including New York Sen. Kirsten Gillibrand and former Colorado Gov. John Hickenlooper, have left the contest, and others seem to be limping along on life support. More may be gone fromthe campaign by mid-October.

Q. At least the NFL season is underway. There’s 22 on the field each play.

A. Plus more colorful uniforms and a better halftime show.