WASHINGTON — Senate Majority Leader Harry Reid and House Speaker Nancy Pelosi both predicted a swift end to the Democratic presidential campaign once South Dakotans and Montanans cast the last ballots of the marathon primary season on Tuesday, saying there is little support among party leaders for a drawn-out fight by Sen. Hillary Rodham Clinton of New York to secure support from unpledged superdelegates.

Reid of Nevada and Pelosi of California, in separate events during political travels in San Francisco, suggested the race is likely to end next week — a conclusion that almost certainly means Sen. Barack Obama of Illinois would secure the Democratic nomination, given his narrow but comfortable lead in both pledged delegates and superdelegates.

In an interview yesterday with KGO Radio promoting his new book, Reid said he had spoken about the campaign in recent days with both Pelosi and Democratic National Committee Chairman Howard Dean. "We agree there won't be a fight at the convention," he said.

Later, at the Commonwealth Club, Reid predicted definitively that the race would conclude shortly after the South Dakota and Montana contests, but he did not say whom he thought the nominee would be. "By this time next week, it'll be all over, give or take a day," Reid said.

Pelosi, in an hourlong meeting with the San Francisco Chronicle's editorial board, predicted the nominee would emerge within a week of the last votes being cast next Tuesday. "I think it is all going in the right direction," she said in the Wednesday interview, which was published yesterday. She said it would be resolved "in an orderly fashion" as early as next week.

Pelosi was adamant that the race would not last through August and the convention in Denver.

"We cannot take this fight to the convention," she said. "It must be over before then."

Currently, the magic number for the nomination is 2,026 delegates. Obama campaign officials say they believe they will be within roughly 10 delegates of that number after voting this weekend in Puerto Rico and June 3 in Montana and South Dakota. That figure could grow if the DNC bylaws panel agrees this weekend to seat as many as half of the delegates from Michigan and Florida, which were stripped of all their delegates because they pushed their primaries into January in violation of DNC rules.

Reid and Pelosi endorsed the idea of giving some partial recognition to Michigan and Florida, but Pelosi — who will chair the convention — said there must be some punishment for their decision.

"If you have no order and no discipline in terms of party rules, people will be having their primary in the year before the presidential election," she said. "So there has to be some penalty."