Biden And Sanders Amp Up Criticism As Polls Show Them Separating From Field

Former Vice President Joe Biden, left, and Vermont Sen. Bernie Sanders participate in a Democratic presidential primary debate in Des Moines, Iowa, on Jan. 14. The two septuagenarians have sparred in recent days about Social Security.

The two Democratic presidential candidates are increasing their scrutiny of each other’s long records.

(Image credit: Robyn Beck/AFP via Getty Images)