(Reuters) - Former U.S. Democratic presidential candidate John Edwards endorsed Barack Obama's White House bid on Wednesday after being heavily courted by both Obama and rival Hillary Clinton.

The race for the 2008 Democratic presidential nomination may be settled by superdelegates -- members of Congress and other party insiders free to vote for whom they want at August's Democratic nominating convention in Denver.

Fewer than 250 of the 796 superdelegates have yet to endorse either Clinton or Obama. Here are some of the high-profile Democrats who have not yet taken a stand on who should be the party's nominee.

* U.S. House of Representatives Speaker Nancy Pelosi of California. She has drawn complaints from some Clinton supporters for saying members of Congress should reflect the will of the people in their districts in deciding which candidate to back.

* U.S. Senate Democratic Leader Harry Reid of Nevada. In a recent interview with National Public Radio, Reid said superdelegates should vote for whomever they want.

* Former Vice President Al Gore, the Democrats' failed 2000 presidential candidate; in 2004, Gore backed Howard Dean, who lost the Democratic nomination to John Kerry.

* Democratic National Committee Chairman Howard Dean. Like other top DNC officers, party rules require Dean to remain neutral until someone wins the nomination.

* Sen. Joe Biden of Delaware and Rep. Dennis Kucinich of Ohio; both made failed bids for this year's Democratic presidential nomination.

* Former President Jimmy Carter, who while officially uncommitted, has dropped hints he supports Obama.