EVANSVILLE, Ind. (AP) _ 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.

"I do see you, I do hear you," she told supporters in Merrillville, Ind., speaking outside the local fire station as a dozen firefighters looked down on her from the fire truck behind her.

She pressed her proposal for a federal gas tax holiday that Obama has dismissed as a gimmick, one of the few issues where the two Democrats clearly diverge.

"It's a stunt," the Illinois senator said in Evansville. "It's what Washington does."

Obama's stance was backed up by 230 economists who released a letter Monday opposing the temporary tax break, which would take 18.4 cents off the price of a gallon if consumers got the full savings at the pump. The signers included four Nobel Prize winners and economic advisers to presidents of both parties.

Clinton shrugged off the blistering reviews from policy makers, industry experts and editorial writers.

"I believe we should start standing up for the majority of Americans who are paying the outrageous gas prices," Clinton said. "I'm ready to take on the oil companies."

Obama hurtled from Indiana to North Carolina and back.

"I want your vote. I want it badly," he pleaded on a factory floor in Durham, N.C., one of many settings drawing the working-class voters he needs.

Obama capped his day with a rain-soaked, get-out-the-vote rally in Indianapolis featuring Motown legend Stevie Wonder, followed by a visit to a factory for the midnight shift change.

Standing at the gates outside the Auto Components Holding plant, partly owned by Ford, Obama shook hands one-by-one with employees as they left. "If I got your vote, it would mean a lot," Obama told them.