INDIANAPOLIS - Democratic front-runner Barack Obama swept to victory in the North Carolina presidential primary Tuesday night and lengthened his lead in the delegate race. Hillary Rodham Clinton led in Indiana as she struggled to make up lost ground.

Obama was winning 63 percent of the vote in North Carolina, a triumph that mirrored earlier wins in Southern states with large black populations. He won at least 31 delegates, and Clinton at least 20, with 139 still to be awarded in the state.

That made Indiana a virtual must-win Midwestern state for the former first lady, hoping to counter Obama's persistent delegate advantage with a strong run through the late primaries.

Returns from 63 percent of Indiana precincts showed Clinton with 54 percent of the vote to 46 percent for Obama.

By DAVID ESPO and LIZ SIDOTI, Associated Press, May 6, 2008