Like marathoners on their second wind, Barack Obama and Hillary Rodham Clinton raced for advantage until the final hours in the campaign for the Indiana and North Carolina primaries Tuesday.

Voters in both states are settling the largest remaining contests in a Democratic presidential nomination struggle that has dragged improbably into spring.

There was little if any expectation that the primaries would settle the big, messy picture. Both Clinton and Obama predicted they’d still be campaigning in June.

Clinton, at her scrappiest when her campaign is on the line — which it has been for weeks — brought a full-throated roar to a series of events in a day of frantic travel spilling into the wee hours Tuesday.

A wealthy inside-Washington veteran, the former first lady worked hard to make common cause with blue-collar voters crucial to Tuesday’s outcome.