Democrats’ divisions test Biden’s front-runner strength

Rep. Tulsi Gabbard, D-Hawaii, and Washington Gov. Jay Inslee chat during a break in the debates. (AP Photo/Paul Sancya)

Former Vice President Joe Biden listens as Sen. Kamala Harris, D-Calif., speaks during the second of two Democratic presidential primary debates hosted by CNN Wednesday in the Fox Theatre in Detroit. (AP Photo/Paul Sancya)

DETROIT — The ideological divisions gripping the Democratic Party intensified on Wednesday as presidential candidates waged an acrimonious battle over health care, immigration and race that tested the strength of early front-runner Joe Biden’s candidacy.