WASHINGTON — Senator Clinton heads into the final two days of the primary campaign with a victory in Puerto Rico and a bold declaration: that more Democrats across the country have cast their votes for her than for the party’s likely nominee, Senator Obama.

The New York senator yesterday won the Puerto Rico primary overwhelmingly, earning more than twice as many votes as Mr. Obama in a contest in which she was heavily favored. Mrs. Clinton carried 68% to Mr. Obama’s 32% amid light voter turnout, a departure from most of the Democratic primaries to date.

RELATED: After Puerto Rico Win, Clinton Boasts of Popular Vote

Despite the lopsided loss, Mr. Obama’s campaign projected he would pick up 15 delegates from Puerto Rico, moving him closer to clinching the Democratic presidential nomination. After the last two primaries tomorrow in Montana and South Dakota, Mr. Obama will likely need the support of as few as 30 superdelegates — out of about 170 who remain uncommitted — to reach 2,118, the number of delegates needed for the nomination.

With her prospects for gaining delegates increasingly dim, Mrs. Clinton is turning to a different metric as she makes the closing argument for her candidacy.

She used yesterday’s result to claim victory in the nationwide popular vote, suggesting that party leaders would be honoring the will of the people should they anoint her as the Democratic presidential nominee.

“We are winning the popular vote. Now there can be no doubt. The people have spoken, and you have chosen your candidate,” Mrs. Clinton said to cheers at a victory rally in San Juan.

The former first lady’s assertion of a popular vote win is open to question, however. She leads Mr. Obama in total votes cast only when including the penalized primaries in Florida, where neither candidate campaigned in advance of the January election, and in Michigan, where Mr. Obama’s name was not even on the ballot. The Illinois senator’s Michigan total is thus zero, although many of his supporters likely registered their vote as “uncommitted.”

Mrs. Clinton acknowledged that Mr. Obama would end the primary campaign with more delegates, and as she did following her victory last month in Kentucky, she appealed directly to the superdelegates, posing a series of questions she implored them to consider as they choose sides in the coming days.

“Which candidate best represents the will of the people who voted in this historic primary?” she asked. “Which candidate is best able to lead us to victory in November? And which candidate is best able to lead our nation as our president in the face of unprecedented challenges at home and abroad?”

Mrs. Clinton offered no clues about her plans should her final argument fall short among party leaders. She made no mention of dropping out of the race, nor did she suggest she would fight for the nomination through the Democratic National Convention in late August.

She also avoided talk of the allocation of delegates from Florida and Michigan made Saturday by the DNC’s Rules and Bylaws Committee. After a long and at times heated meeting, the panel voted to recognize the Florida election and agreed to a compromise proposed by party leaders in Michigan. Both states were stripped of 50% of their total delegates, and Mrs. Clinton gained some but not all of the delegates she had hoped to amass from the states.

Her campaign officials yesterday criticized the Michigan decision, saying the move to allocate delegates only partially in accordance with the election results violated a “bedrock principle” of democracy and amounted to stealing delegates won by Mrs. Clinton. The campaign’s chief delegate counter, Harold Ickes, reiterated on NBC’s “Meet the Press” that Mrs. Clinton will “reserve her rights” to appeal the decision to the Credentials Committee of the party convention.

Mr. Obama acknowledged the results in Puerto Rico during an afternoon rally in South Dakota, where he was campaigning in advance of tomorrow’s primary there. He said he phoned to congratulate Mrs. Clinton, but he praised her in terms that suggested the race was over.

Mrs. Clinton is an “outstanding public servant” who has “worked tirelessly during this campaign,” he said. “She is going to be a great asset when we go into November.”

With the nomination nearly in hand, Mr. Obama is planning to spend the final primary night in St. Paul at the site of the Republican National Convention this summer. Whether he will be able to declare an outright victory, however, will depend on how many superdelegates he can secure over the next two days. In television interviews yesterday, his advisers predicted the party would have a nominee by the end of the week, but they did not say if they expected Mr. Obama to reach the magic number by tomorrow night.

At least one prominent Democrat who has remained neutral, Rep. James Clyburn of South Carolina, has said he plans to announce his endorsement during the day tomorrow.

Mr. Obama picked up two more superdelegates yesterday: Gwethalyn Phillips of Maine and Yvonne Gates of Nevada.