WASHINGTON — Citing Democratic rules, national committee Chairman Howard Dean on Tuesday said the superdelegates who are poised to select the party's presidential nominee are free to back whomever they wish at the end of the primaries, regardless of who leads in the popular vote or pledged delegates.

"They should use whatever yardstick they want," Dean said. "That's what the rules provide for."

Asked about Sen. Hillary Rodham Clinton's suggestion that superdelegates should exercise independent judgment and not feel bound by the standings after June 3 — when the primary season ends — Dean replied: "That's what the rules say, and I enforce the rules."

He also said superdelegates are free to weigh the disputed primary results in Florida and Michigan. The two campaigns have spent weeks wrangling over a plan that would seat delegates from the states, which violated party guidelines by voting earlier than allowed.

Although his comments were a restatement of party rules, Dean's stance undercut an argument pressed by Sen. Barack Obama and his backers. They have said the candidate who has the most pledged delegates should automatically win the support of any uncommitted superdelegates after primary balloting ends.

Earlier Tuesday, House Speaker Nancy Pelosi, D-Calif., appeared to back away from that view. "These superdelegates have the right to vote their conscience and who they think would be the better president, or who can win," Pelosi said on ABC's "Good Morning America."

Pelosi — who like Dean has remained neutral in the nominating fight — recently angered some Clinton supporters when she seconded Obama's position that superdelegates should be guided by the vote for pledged delegates. Several major Democratic donors sent Pelosi a letter last week objecting to that stance.

Speaking Tuesday on National Public Radio, Pelosi dismissed the letter as unimportant. Dean agreed, rejecting the characterization of those who had called it a political ransom note.

Neither Obama nor Clinton appears likely to win the 2,024 delegates needed to secure the nomination. That would leave the outcome in the hands of 794 superdelegates, party leaders whose standing gives them a say.

Obama leads Clinton in delegates chosen in primaries and caucuses, but Clinton leads Obama in superdelegate support, according to an Associated Press count. Overall, Obama has 1,632 delegates, 1,414 of them pledged, to Clinton's 1,500, 1,250 of them pledged, according to the latest AP tally.

About 330 superdelegates remain uncommitted, and Dean said his only counsel was that they make up their minds — "for their country's sake and their party's sake" — by July 1.