“Liberal, moderate divide on display in Democratic debate

The prime-time debate also elevated several struggling candidates, giving them a chance to introduce themselves to millions of Americans who are just beginning to follow the race.

Biden dominated significant parts of the evening, responding strongly when the liberal senators who are his closet rivals — Bernie Sanders and Elizabeth Warren — assailed him and his policies.

Unlike prior debates, where Biden struggled for words and seemed surprised by criticism from fellow Democrats, he largely delivered crisp, aggressive responses. He called Sanders “a socialist,” a label that could remind voters of the senator’s embrace of democratic socialism. And Biden slapped at Elizabeth Warren’s proposed wealth tax.

A two-term vice president under Barack Obama, Biden unequivocally defended his former boss, who came under criticism from some candidates for deporting immigrants and not going far enough on health care reform