MIAMI — It's all about Joe Biden now.

The former vice president could solidify his status as the favorite to win his party's presidential nomination with a strong debate performance here Thursday night.

But more than two months into a campaign noteworthy for the candidate's limited interaction with the public and the news media, Biden could also walk out severely hobbled.

Voters, Biden's Democratic rivals and President Donald Trump will be looking for any sign that he has lost heat off his fastball as a candidate — a gaffe, a moment of indecision or an inability to explain either his past or his plans for the future.

Any slip could be costly because Biden has built his lead in the polls in part on the perception of strength, and because he has struggled in recent weeks to effectively communicate about his change on a decades-old position in favor of restricting federal funding for abortion and his relationships with segregationist senators during his first terms in the Senate.

Even a lack of luster could spell trouble for the 76-year-old former senator from Delaware.

Already, Trump has nicknamed him "Sleepy Joe," and Sen. Elizabeth Warren of Massachusetts, who has surged into third place in the Democratic primary in most national polls, turned in a passionate and largely mistake-free round in Wednesday's first-night debate here at the Adrienne Arnsht Center for the Performing Arts. In doing so, she laid out a path for Biden on Thursday.

"All he needs to do is come out without being damaged, and that is a victory," said Chris Kofinis, a veteran Democratic strategist who worked on presidential campaigns for Wesley Clark and John Edwards. "But he is going to get — unlike the first debate, where Warren was not really the center of attention — he’s going to get the attention and pointed criticisms."

If the first-night discussion is any indication, some of the nine candidates who share the stage with Biden on Thursday may be more than willing to use portions of their time to try to put him on the defensive. On Wednesday, several hopefuls took turns sniping at former Rep. Beto O'Rourke of Texas over his understanding of complex immigration and health care issues, setting the stage for a more direct exchange of volleys between candidates than has been typical in the early months of the primary.

To the extent that any of the candidates have taken on Biden so far, Sen. Bernie Sanders, currently second to Biden in polling, has been the most open about contrasting their records and philosophies. In particular, Sanders has gone after Biden on his vote for the Iraq War and support for trade deals.

But there's danger for Sanders in getting too aggressive with Biden, who remains broadly popular among Democrats. That creates a conundrum for the Vermont independent, who is a self-described democratic socialist. It's hard for him to damage Biden without taking shots that have the potential to boomerang.

Right now, Biden sits at 32 percent in the Real Clear Politics average of national polls, with Sanders next at 16.9 percent and Warren in third at 12.8 percent. Two more candidates who will share the stage with Biden and Sanders — Sen. Kamala Harris of California and Mayor Pete Buttigieg of South Bend, Indiana — round out the top five, at 7 percent and 6.6 percent, respectively.

Harris was critical of Biden after he said last week that he had formed working relationships with two segregationist senators, James Eastland, D-Miss., and Herman Talmadge, D-Ga., during his early days in the Senate despite disagreeing with them. While Biden did not espouse similar views on white supremacy, he often voted with those lawmakers and other Democratic and Republican members of a Southern bloc on busing and other matters related to desegregation in the 1970s and ’80s.

In 1975, as NBC News reported this week, Biden wrote an amendment that would have stopped the federal government from using its funding power to require schools to put white and black children in the same classrooms. The Biden amendment was adopted by the Senate but killed in the House.

Harris, whose father was born in Jamaica, said that Biden's fond recollections of Eastland and Talmadge "deeply" concerned her.

"If those men had their way, I wouldn’t be in the United States Senate," she said.

.@SenKamalaHarris is asked if she’s concerned about Biden’s segregationist remarks: “Yes it concerns me deeply. If those men had their way, I wouldn’t be in the United States Senate and on this elevator right now.” — Mariam Khan (@MKhan47) June 19, 2019

Buttigieg has been struggling with his own racially charged controversy in recent days.

He has faced criticism after a 54-year-old black man, Eric Jack Logan, was shot and killed by a white South Bend police officer, Sgt. Ryan O'Neill. At a town hall meeting over the weekend, residents hurled profanities at Buttigieg and the city's police chief — as well as one another — as black residents expressed frustration over allegations of years of systemic injustice.

Beyond the four marquee names in the debate, two Coloradans, Sen. Michael Bennet and former Gov. John Hickenlooper, New York Sen. Kirsten Gillibrand, California Rep. Eric Swalwell, celebrity spiritual adviser Marianne Williamson and businessman Andrew Yang will round out the picture on Night Two.

Williamson and Yang are the big wildcards because they have never held political office and therefore have little to lose in terms of making big proposals or launching major attacks. Yang is a proponent of a universal basic income, and Williamson favors slavery reparations for African Americans.

But most of the attention will center on Biden and his ability to weather the storm that is sure to come his way.

"The more he gets brought down to a debate between him and his opponents, it will help his opponents," Kofinis said, arguing Biden should focus his fire on Trump. "Whether you can execute that when the punches are coming from all sides, that’s a different question."