GRAND RAPIDS, Mich. — Democrat John Edwards endorsed former rival Barack Obama yesterday, a move designed to help solidify support for the party's likely presidential nominee even as Hillary Rodham Clinton refuses to give up her long-shot candidacy.

The surprise endorsement came a day after Clinton defeated Obama by more than 2 to 1 in the West Virginia primary, and it helped the Obama campaign steer much of the evening news coverage away from that subject. The West Virginia outcome highlighted Obama's challenge in winning over "Hillary Democrats" — white, working-class voters who also supported Edwards in significant numbers before he exited the race in late January.

Edwards made the carefully timed announcement at an Obama rally here, as the Illinois senator campaigned in a critical general election battleground state. His appearance, announced just an hour before the huge rally was to begin, brought the crowd to frenzied cheers.

"Democratic voters have made their choice, and so have I," Edwards said.

He had kind words for Clinton, saying the New York senator had shown fortitude in her campaign and urged Democrats to unite to defeat presumed Republican nominee John McCain.

Edwards invoked themes from his abandoned campaign of ending poverty, equal education for all children and universal healthcare.

"There's one who understands the need to create one America, not two Americas, and that man is Barack Obama."

Edwards, who dropped out of the campaign in late January after several third-place finishes, had 19 pledged delegates, but they are all free to make their own choice at the convention. Still, Edwards' endorsement is likely to carry weight.

Obama followed with a fiery speech with similar populist themes aimed at appealing to working-class voters.

He vowed to end the war in Iraq in 2009 and said the U.S. will treat homecoming veterans better than President George W. Bush's administration has treated injured vets.

He vowed to cut poverty in half as president.

"You should never be hungry. You should never be homeless. You should never face the threat of poverty," he said.

Like Edwards, Obama railed against corporate special interests that he said have taken over power in Washington at the expense of ordinary Americans.

The Associated Press and the Detroit Free Press contributed to this report.