(REUTERS) -- Democrat Jeanne Shaheen won re-election to the U.S. Senate from New Hampshire on Tuesday, beating back an aggressive campaign from Republican Scott Brown in a bittersweet victory as her party lost its majority in the upper chamber of Congress.
Brown was a little-known Massachusetts state legislator before he burst onto the national stage in 2010 when he won the U.S. Senate seat that liberal Democratic champion Edward Kennedy had held for half a century. Brown lost his 2012 re-election bid and moved north late last year to New Hampshire, where he grew up, with an eye on Shaheen's seat.
Shaheen's campaign had focused on Brown's recent return to the state, saying New Hampshire should not be viewed as a "consolation prize." Brown worked to tie Shaheen closely to President Barack Obama, who is unpopular in New Hampshire.
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"Tonight, the people of New Hampshire chose to put New Hampshire first," Shaheen told a crowd of supporters in Manchester. "I promise you I will work with anyone in the Senate, Democrat, Republican, independent to get things done for New Hampshire."
Shaheen's long history in New Hampshire, where she previously served as governor, likely helped her campaign, said Peter Ubertaccio, chairman of the political science department at Stonehill College in Easton, Massachusetts.
"She is not a polarizing figure and they were not willing to throw her out," Ubertaccio said. "The quickness with which (Brown) left Massachusetts, set up shop in New Hampshire and then decided to run, even though he has a history here, worked against him. New Hampshire voters like to get to know their politicians."
Brown, 55, and Shaheen, 67, staged campaign blitzes over the past few days, with former Secretary of State Hillary Clinton stumping for Shaheen over the weekend.
Shaheen said her priorities in her second term in the Senate would include pushing for new U.S. energy policies "to end our reliance on oil and coal and fossil fuels," as well as to make higher education more affordable.
Both parties saw the seat as critical to taking a majority in the Senate. But the big names in both parties have an extra incentive to travel to the state, which holds the first presidential nominating primary.
Potential Republican White House hopefuls, including New Jersey Governor Chris Christie and U.S. Senator Rand Paul of Kentucky, visited to endorse Brown.
But voters like Jerri Dalessio, 68, took a skeptical view of Brown's ties to the state where he grew up but only returned to recently.
"I just think Shaheen supports New Hampshire," Dalessio said.
Brown offered no hints as to his political future in his concession speech, which came after hours of vote-counting in which it was unclear who would take the race.
"It was up, it was down, it was all around waiting," Brown said, adding that he would still celebrate his party's national showing on Tuesday.
"It is a good night for America," he said. "It looks like the Senate has changed over to Republican hands."