Former Sen. John Edwards endorsed one-time presidential rival Barack Obama yesterday in the Democratic race, a move Gov. Timothy M. Kaine said could help the Illinois senator lure white working-class voters.

"John Edwards' campaign was a match with the Obama campaign -- a campaign about change, about people inside the Beltway not making the decisions," Kaine, a national co-chairman of the Obama organization, said in an interview.

"Senator Edwards did a really good job appealing to white, working-class voters, and that will help Senator Obama."

Such voters were a key constituency for Edwards, a populist trial lawyer and 2004 Democratic vice presidential nominee whose home state, North Carolina, went solidly for Obama in last week's primary.

Edwards appeared with Obama last evening at a raucous rally in Grand Rapids, Mich.

"We are here tonight because the Democratic voters have made their choice and so have I," Edwards said.

Edwards said Obama "stands with me" in a fight to cut poverty in half within 10 years.

The Edwards endorsement came one day after Sen. Hillary Rodham Clinton of New York claimed a lopsided victory over Obama in West Virginia, a heavily white state with a vast blue-collar electorate -- a vote that in recent cycles has drifted to Republicans.

Kaine, reached by telephone, said the Edwards endorsement is the latest sign that the nomination fight between Obama and Clinton is over.

"I really believe last week, in Indiana and North Carolina, was the mathematical end of the campaign," Kaine said. "The Edwards endorsement signifies that."

Kaine is one of five Virginia superdelegates pledged to Obama. Five others back Clinton, and six are undecided.

Mame Reiley of Alexandria, a superdelegate pledged to Clinton, disagreed with Kaine.

"I don't think it ends it," she said of the Edwards endorsement.

Susan Swecker of Richmond, another Clinton superdelegate, said "Senator Edwards and his wife, Elizabeth, are very popular and respected in the Democratic Party," but Edwards' endorsement may have come too late to have much of an impact.

Having said that, however, Swecker said both campaigns had sought his endorsement, so "you would rather have it than not."

Clinton campaign Chairman Terry McAuliffe -- one of Clinton's Virginia superdelegates -- said in a statement, "We respect John Edwards, but as the voters of West Virginia showed last night, this thing is far from over."

Jerome Wiley-Segovia, an uncommitted Virginia superdelegate, said Edwards' endorsement "is definitely important."

Segovia said he will continue to remain neutral because he is on the party's rules committee. The committee will meet this month to decide whether to seat delegates from Florida and Michigan. The national Democratic Party has not recognized results from primaries in those states.

Contact Jeff E. Schapiro at (804) 649-6814 or jschapiro@timesdispatch.com.

Staff writer Tyler Whitley and the Associated Press contributed to this report.