Rivals criticize Biden in debate for policies of past

WASHINGTON — Sandwiched between a heated but often-disjointed argument over health care and an inconclusive discussion of climate change, 10 Democratic candidates for president grappled Wednesday evening with race — their party’s greatest potential source of strength and also its most fraught division.

Never in the history of major-party presidential debates has so diverse a group of candidates appeared on a presidential debate stage: three women and five people of color, including a Latino former Cabinet member and two black U.S. senators.

That lineup showed the face of the Democrats’ multi-racial and multiethnic coalition, which provides a central advantage for the party in a country whose nonwhite population is rapidly growing, especially in the metropolitan areas where most Democrats live.

But as Wednesday’s debate showed when it turned to issues of criminal justice, school segregation and immigration, multiracial coalitions can be fractious. That’s especially true when the president running for re-election has elevated racial conflict to the top of the agenda by persistently playing on the country’s divisions.

For the second consecutive debate, it was the leader in the polls, former Vice President Joe Biden, who took most of the incoming fire on those issues. As a 76-year-old white man seeking to lead a diverse party, and as a politician with nearly half a century of positions to defend — many of which are