There were opportunities and risks for front-runner Hillary Clinton, who had to confront some voters' doubts; Bernie Sanders, who sought to broaden his appeal; and Lincoln Chafee, Martin O'Malley and Jim Webb, who were introduced to an audience of millions.
REPORT CARD
Lincoln Chafee, former senator and governor: His closing statement, with its emphasis on his experience and judgment, was his highlight. A reluctance to interrupt made him seem like a bystander for much of the debate, and he stumbled over his explanation of a long-ago Senate vote.
Hillary Clinton, former secretary of state: Questioners seemed bent on creating a Clinton-Sanders duel, and she took full advantage, displaying a command of issues. Perhaps mindful of recent critiques of her personality, she was expansive, smiling and quipping often.
Martin O'Malley, former governor, mayor: His delivery was mostly deadpan, but he managed frequent references to his governing experience. He conveyed optimism, particularly in his final words, but mentions of an obscure banking law had to be translated by moderators.
Bernie Sanders, senator: His willingness to interrupt, intensity and ample attention from questioners gave him almost as much airtime as Clinton. His serious mien only occasionally yielded to levity, and he sometimes referred to himself in the third person.
Jim Webb, former senator, Navy chief: He came across as a little gruff and visibly frustrated by his inability to command the stage; at one point he lamented, "This hasn't been equal time." No other candidate can match his military service, which he successfully stressed.
ON THE ISSUES
Hillary Clinton's e-mails