The Democratic presidential primary is no longer dominated by a single, unequivocal front-runner, last weeks polling suggests, breaking the months of relative stasis during which former Vice President Joe Biden carried an extensive lead over the rest of the field.

Biden, who has survived controversies over his behavior toward women and his comments on segregationist leaders without notable dents, isnt exactly cratering now: Hes still at the top of virtually all national polls . Nor does he seem to have picked up much newfound enmity among voters. But the first primary debates appear to have gone some way toward leveling off a top tier among the Democratic contenders.