Amid Insults and Interruptions, Sanders Absorbs Burst of Attacks in Debate

For the second consecutive debate, Mr. Bloomberg visibly sighed and rolled his eyes as Ms. Warren assailed his variegated political history and demanded fuller disclosure from Mr. Bloomberg’s company about its treatment of women. Mentioning his history of giving large campaign contributions to Republicans, Ms. Warren said, “The core of the Democratic Party will never trust him.”

“He has not earned their trust — I will,” Ms. Warren said, noting that Mr. Bloomberg had opposed her own campaign for the Senate in 2012.

Mr. Bloomberg tried to pivot away from Ms. Warren’s criticism to make an argument about his own experience, alluding to his role taking over New York City after the Sept. 11, 2001, terrorist attacks. “I have the experience, I have the resources and I have the record,” Mr. Bloomberg said, “and all of the sideshows that the senator wants to bring up have nothing to do with that.”

But as in the debate last week, Mr. Bloomberg’s loose phrasing offered Ms. Warren the chance to throw a hard counterpunch: What Mr. Bloomberg called a “sideshow,” she said, involved matters as serious as pregnancy discrimination.

Mr. Bloomberg, clearly seeking to recover from his lackluster debate performance, offered a series of well-rehearsed lines to try to demonstrate more aptitude for the medium. Some of them fell flat, including the one about how he was amazed that the other “contestants” all showed up after he had done “such a good job last week.”

Mr. Bloomberg is not on the ballot in South Carolina on Saturday, but his strength as a candidate in the Super Tuesday primaries next week may depend in large part on whether he can maintain a solid bloc of support among black voters, or whether African-American voters who have drifted away from Mr. Biden over the past month return to his side in the coming days.

Asked directly about his support from black voters, the cornerstone of his coalition and a group that will make up over half of the Democratic electorate on Saturday, Mr. Biden projected confidence.