Hillary Clinton's win in South Dakota was a blow to three of the state's Democratic leaders who endorsed Barack Obama and lent him their clout. But that loss was overshadowed by a much bigger win for Obama on Tuesday.

South Dakota Sen. Tim Johnson, Rep. Stephanie Herseth Sandlin and former Sen. Tom Daschle all endorsed Obama in the Democratic presidential primary, saying they like his message of party unity. Daschle, who narrowly lost re-election in 2004, is a top adviser to Obama, and many of his former staffers are helping run that campaign.

Clinton's win in South Dakota is bittersweet and also somewhat meaningless, however, as Obama on Tuesday earned enough delegates to win the Democratic nomination.

"I am thrilled," said Daschle, who endorsed Obama more than a year ago. "I think this is very good for the country."

He said he was surprised that Clinton won South Dakota but said it was difficult for Obama as he was beginning his national campaign while he was running in the state's primary. Obama "had more of a challenge than the Clintons," Daschle said.

Johnson, Herseth Sandlin and Daschle all are so-called superdelegates, or party insiders who can cast a ballot for the candidate of their choice at the party's national conventions this summer.

Aides to Johnson said he voted for Obama but would keep an earlier promise to support the winner of the state's primary if the nomination is still contested at the convention.

That outcome is unlikely, however, after Obama cinched the nod on Tuesday.

In a statement, Johnson said, "It is right that the voters of South Dakota were heard and made their feelings known.

"Now this historic nominating process has officially come to an end and I believe candidates and the party will unify and move forward."

In her statement, Herseth Sandlin did not mention Clinton.

"This has been an exciting and historic primary process, and I am thrilled that South Dakota got to play such an important role," she said. "Senator Obama will be a strong and effective leader on issues important to rural America, and I look forward to working with him to advance South Dakota's priorities."