MANCHESTER, N.H. — A large recent influx of potential new voters could alter the New Hampshire electorate and tip tomorrow’s primary contest in favor of Senator Obama.

Between 2001 and 2006, 207,000 people migrated to New Hampshire, which has a population of 1.3 million, and 188,000 departed, the University of New Hampshire’s Carsey Institute, using data from the Census Bureau and Internal Revenue Service, found. The institute identified 145,000 of the state’s new residents as being of voting age and estimated that another 86,000 have turned 18 during the past five years. Many of these potential voters fit the profile — college educated, computer savvy, and professional — of a group that has warmed to outsider-oriented liberal candidates in the past, such as Gary Hart, Howard Dean, and Bill Bradley. Accordingly, demographers and political experts said, the findings spell trouble for Senator Clinton.

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“She is doing best among older people and blue collar people,” a political science professor at the University of New Hampshire, Andrew Smith, said. “These are not the type of people we’re talking about who have moved in.” Mr. Smith, who directs UNH’s survey center and is conducting polls for CNN and WMUR during this election cycle, said the new voters are typically Democratic-leaning independents, called “undeclared” in New Hampshire’s political parlance. The latest CNN/WMUR poll found Mr. Obama beating Mrs. Clinton by 39% to 27%, with Senator Edwards capturing 18% of the vote.

New Hampshire’s secretary of state, William Gardner, has said that he expects 100,000 more voters to cast ballots on Election Day than the previous high water mark for a primary, roughly 400,000 in 2000. Turnout was low in 2004, about 287,000, when there was only a Democratic primary.

A former political consultant to Mr. Bradley, Michael Goldman, said the former New Jersey senator counted on the support of this exact type of voter. “We were always the outsider Democrat, a smart type of voter who would be Obama/Edwards supporters,” Mr. Goldman, a senior consultant to the Government Insight Group, said. “These people tend to be Democrats but are not part of a tribe: labor, teachers, women. They find the Bill Bradleys, the Gary Harts, the Obamas.”

Mr. Obama yesterday exhorted more than 850 voters in Manchester’s Palace Theater to vote for him. “You will have the chance to change America in two days,” he said. Mr. Obama spoke of receiving the support of Republicans in Iowa and mentioned groups out of the voting mainstream that came out and voted for him, including young people and independents. He also took a page out of Republican John McCain’s repertoire, saying he offered “straight talk.”

His candidacy drew praise from voters new to the Granite State’s electoral process. William Stewart, a 28-year-old from Manchester, said he was “pretty certain” he was “going for Obama.” Mr. Stewart, who said he moved to New Hampshire from Tennessee, said that when he “first heard Hillary, I was most impressed, but Obama’s authenticity trumps that.”

David Plunkett, a political independent software engineer who moved to New Hampshire prior to the 2000 election with his wife, said after Mr. Obama’s speech that “Barack’s message of hope for a better America strikes a deep chord for me.”

Later, the pair drove southward to Nashua to hear Mrs. Clinton address what the senator called a crowd of 3,500 people. New York’s junior senator spoke for 15 minutes and then took questions for about another hour and a half. Like a graduate student acing oral exams, Mrs. Clinton provided detailed answers to an almost mind-numbing number of policy questions. The event marked something of a reversal in political strategy; typically, candidates in New Hampshire start with long question and answer sessions and wind up their campaigns with relatively succinct, enthusiastic stump speeches.

“Both Lynn and I were left a little flat by the Hillary thing,” Mr. Plunkett, who said he and his wife were leaning to Mr. Obama, said. They exited the event before it concluded. Another attendee, 18-year-old Morgan Talbott, said she favored Mr. Obama. “I saw him on MTV and I really like the fact that he addressed the Darfur situation,” she said. A senior at Nashua North High School, she added she went to the event at the suggestion of her grandmother, a backer of Mrs. Clinton.

Both candidates are focused on getting their voters out to vote on Election Day. Mr. Obama brought a campaign aide onto the stage with him and asked voters who were still undecided to raise their hands so workers could approach them after his speech. Mrs. Clinton’s campaign on Saturday sent its volunteers and campaign workers out on a widespread door-knocking campaign, an effort aimed at identifying as many supporters as possible.

Mr. Obama also held events in Derry and Exeter, both of which contain a large number of new voters. “Exeter is very much like a college town, the presence of Phillips Exeter means it is chockablock with college graduates and professional workers” likely to support him, a local demographer, Peter Francese said.