Barack Obama collected the support of seven of John Edwards' Democratic convention delegates on Thursday, then gained the backing of four superdelegates and a large labor union as he marched steadily toward the party's presidential nomination.

The fresh support brought Obama's overall delegate total to 1,898, compared to 1,718 for his rival, Hillary Rodham Clinton. It takes 2,026 to clinch the nomination at the party convention in Denver this summer.

Edwards, who bestowed his long-sought endorsement on Obama on Wednesday, won 19 delegates before departing the presidential race in January.

Within hours, Obama picked up the backing of five of them from South Carolina, one in New Hampshire and one in Iowa.

In addition, three superdelegates _ Reps. James McDermott of Washington, and Henry Waxman and Howard Berman of California _ endorsed Obama.

"I believe now is the time to unite behind Barack Obama so we can be in the strongest place possible to win in November," McDermott said.

Waxman said in a statement: "I have the greatest respect and admiration for Senator Clinton and former President Clinton ... It is now clear, however, that the Democratic Party is nearing a broad consensus on our nominee."

Edwards had been backed by the United Steelworkers Union, which announced it would now support Obama. The union has 600,000 active members, many of them blue-collar workers of the type that have favored Clinton in recent primaries.

Obama also picked up the personal endorsement of superdelegate Larry Cohen, the president of the Communication Workers of America union.

Campaigning in Rapid City, S.D., Clinton spoke for the first time about Edwards' endorsement.

"I have a great deal of respect for Senator Edwards," she said in response to reporters' questions. "He and I have a lot in common ... I imagine that Senator Edwards' endorsement will be of some help to Senator Obama in Kentucky, but I think that what matters are the people who actually vote."

Clinton said she had not spoken with Edwards but had spoken with his wife, Elizabeth, about the endorsement. Clinton declined to discuss their conversation.

The delegate and labor support came despite Obama's overwhelming defeat in Tuesday's primary in West Virginia, and suggested that Clinton's argument that she would be a better general election candidate was not finding a receptive audience.

The former first lady is favored to win next week's primary in Kentucky, while Obama is expected to win in Oregon the same day.

The delegates won by Edwards are not bound by his endorsement of Obama, but several said it is important to their decision. Continued...