As expected, House Majority Whip Jim Clyburn (D-S.C.) endorsed Sen. Barack Obama (D-Ill.) in the presidential race Tuesday and sought to rally other unpledged superdelegates to Obama’s side.

Clyburn’s move is an effort to bring a swift conclusion to the presidential race after Tuesday’s final primaries in South Dakota and Montana.

Clyburn, a member of the Congressional Black Caucus, made note of past racial divisions in his lengthy statement of support for Obama over Sen. Hillary Clinton (D-N.Y.).

“Our presidential nominee will accept our party’s nomination on the anniversary of Dr. Martin Luther King Jr.’s historic call for a nation where we are all judged by ‘the content of our character rather than the color of our skin,’” Clyburn said. “Over the next several weeks, our party will have an historic opportunity to transcend these issues that have plagued our nation since its founding and our party for generations.”

Clyburn said it is time to declare a winner in the long-fought presidential contest that hinges largely on superdelegates, many of whom are Members, to the party convention in August.

“United does not mean unanimous; united means recognizing and respecting some realities. And it is a reality that delegates determine the winner. No matter the outcome tonight, Sen. Obama will lead in the delegate count and should be named the nominee.”

A trickle of other superdelegate endorsements are expected throughout the day and night Tuesday.

Obama backers hope their support will put him over the 2,118 delegates he needs to secure the presidential nomination.