(Bloomberg) -- Joe Biden kicks off the most high-stakes week of his campaign so far, as he heads into the first Democratic debate with the opportunity to solidify his front-runner status — or jeopardize it with a gaffe, an inappropriate joke or a tone-deaf comment.

The former vice president doesn't need to win the debate, he just needs not to lose, as his 19 rivals seek to break out of the unprecedentedly large Democratic field by taking him on. And he has given them plenty of ammunition with recent unforced errors such as comments about his civil relationships with segregationist senators in the 1970s and his flip-flop on federal abortion funding.

"The biggest risk and peril for Biden is Joe Biden," said Mary Anne Marsh, a Democratic consultant based in Boston. "He has a proclivity for making mistakes, for not apologizing for them, and then oftentimes not explaining his positions on things."

Biden, 76, benefits from high name recognition, strong relationships with party leaders and a perception that he's the most "electable" Democrat to put up against President Donald Trump, 73. Until now, he has largely been able to stay above the fray, keeping a low-key campaign schedule with sparse events and press interviews. The debates — Biden's first since 2012 — are his chance to show the country he has the gravitas his opponents lack.

But the event follows the toughest stretch for Biden since he started his campaign in April. His remarks about working alongside segregationist lawmakers in the Senate set off several days of attacks from activists and rivals, including Senators Kamala Harris and Cory Booker, the two major black candidates in the race.

Biden had dismissed Booker's demands for an apology, and had instead asked the New Jersey senator to apologize to him. Asked this weekend whether the two candidates needed to "bury the hatchet," Booker said: "There is no hatchet." The issue, however, could carry over to the debates.

"I have a lot of respect and gratitude for the vice president and I want folks to know I have nothing to apologize for when it comes to speaking truth to power, and he's a powerful person," Booker told reporters at a gathering of Democratic candidates in South Carolina on Saturday.

The televised debates on NBC, MSNBC and Telemundo feature 20 Democratic candidates split into groups of 10 on Wednesday and Thursday. Each night will include a mix of top-tier and lower-polling contenders. Biden will appear on Thursday along with Harris and Senator Bernie Sanders and Mayor Pete Buttigieg. The first night will match Senator Elizabeth Warren against former Representative Beto O'Rourke, Booker and Senator Amy Klobuchar.