Hillary Rodham Clinton coasted to a large but largely symbolic victory in working-class West Virginia on Tuesday, handing Barack Obama one of the worst defeats of the campaign yet scarcely slowing his march toward the Democratic presidential nomination. With votes from 98 percent of West Virginia's precincts counted, Clinton was winning 67 percent of the vote, to 26 percent for Obama. Clinton won 20 of the 28 delegates at stake in West Virginia and Obama won eight.