WASHINGTON (Reuters) - Seven Democratic presidential candidates will take the stage in Los Angeles on Thursday in the party’s sixth debate of the nominating contest for the November 2020 U.S. election.

FILE PHOTO: U.S. Democratic presidential candidate Pete Buttigieg holds a town hall event in Creston, Iowa, U.S. November 25, 2019. REUTERS/Scott Morgan/File Photo

The debate is likely to come on the heels of the U.S. House of Representatives’ historic debate and vote on the articles of impeachment against President Donald Trump charging him with attempting to encourage the government of Ukraine to interfere with the election.

Here are some things to keep an eye on:

A LACK OF DIVERSITY

The debate may be more notable more for who isn’t on the stage rather than who is.

Six of the seven candidates who qualified to participate are white, with one Asian-American (Andrew Yang) and no black or Latino candidates – perhaps a bad look for a party that prizes itself on its diverse electorate.

The withdrawal of U.S. Senator Kamala Harris from the race and the failure of U.S. Senator Cory Booker and former Housing Secretary Julian Castro to qualify for the debate has renewed questions about the fairness of the criteria set by the Democratic National Committee.

But Joel Payne, a Democratic strategist who worked for Hillary Clinton in 2016, said the process is working as it should by winnowing the field, which still consists of 15 candidates overall.

“The party has tried really hard to make this as open and diverse a process as possible,” Payne said. “Candidates of color raised competitive sums of money and had as much coverage as many of the candidates.”

BUTTIGIEG VS. WARREN

By far, the most open hostility between any two candidates in the race at the moment exists between Pete Buttigieg, the mayor of South Bend, Indiana, and U.S. Senator Elizabeth Warren of Massachusetts.

As Buttigieg has shown strength in the early voting states of Iowa and New Hampshire, Warren has slammed him for not releasing a list of his top fundraisers or his clients while working at consulting firm McKinsey & Co. He has now disclosed both.

Buttigieg, in turn, has repeatedly blasted Warren for her support for Medicare for All, the single-payer, government-sponsored plan she supports.

“Will it be as contentious as it has been when they haven’t been face-to-face?” said progressive strategist Andrew Feldman, who has worked for labor unions such as the American Federation of Teachers and Service Employees International Union. “That could create a new dynamic in the race.”

Feldman said former Vice President Joe Biden and U.S. Senator Bernie Sanders have benefited from the Buttigieg-Warren spat, with both men seeing their standing in opinion polls solidify in recent weeks. He wondered if perhaps Warren and Sanders might begin going after each other.

“At some point, the two liberal lions in this race are going to have to figure out how to peel off the other’s supporters,” Feldman said.

TIME ON THEIR SIDE?

Having fewer candidates on stage for a three-hour debate means that, on aggregate, contenders will have more time to address voters than ever before.

That could benefit U.S. Senator Amy Klobuchar, who has been looking for an opportunity to build momentum for her campaign. Yang’s campaign, too, believes this is an opportunity for the outsider candidate to break through, according to a memo released last week.

The debate is important for marginal candidates like Klobuchar and Yang for another reason: It will be their last national appearance before the end-of-the-year fundraising deadline.

But will viewers feel fatigued by round-the-clock impeachment coverage and look to watch a favorite holiday film instead of another round of candidate sparring?

The television ratings for the last Democratic debate in Atlanta were the lowest, with 6.6 million viewers tuning in. By contrast, around 18 million watched the second night of the Miami debate in June.