BOSTON -- Republican Senate candidate Scott Brown has surged ahead of his Democratic opponent Martha Coakley, according to a new poll released Thursday night.

Brown leads Coakley by a margin of 50 percent to 46 percent, the Suffolk University/WHDH-TV poll found. It is the first poll to show Brown, who had been thought a long-shot underdog, leading the race.

It raises the possibility of an historic political upset in Massachusetts.

“It’s a massive change in the political landscape,” David Paleologos, director of Suffolk’s Political Research Center, told The Boston Herald.

Paleologos told the newspaper that the poll shows high numbers of independent voters turning out on election day, which benefits Brown, who has 65 percent of independents compared to Coakley’s 30 percent.

The poll has a 4.4 point margin of error, which means Coakley could win the race, Paleologos said.

Joseph L. Kennedy, the unenrolled candidate in the race, was preferred by 3 percent of those surveyed.