Former Sen. Scott Brown (R-Mass.), who announced last week he was forming an exploratory committee to run for the Senate in New Hampshire, starts his bid as the underdog.
An automated Rasmussen poll released Monday finds incumbent Sen. Jeanne Shaheen (D-N.H.) leading Brown, 50 to 41, among likely voters. Another poll from the American Research Group puts her up 50 to 38 among registered voters.
Half of the dozen surveys taken on the matchup so far have found Shaheen leading by 10 points or more. With one exception -- a January poll that found the race tied -- all put her ahead. HuffPost Pollster's tracking model gives her a lead of just over 9 points.
There's plenty of time for the the race to change, and outside groups on both sides are spending heavily on negative ads.
Unlike many other 2014 matchups, however, New Hampshire features two candidates already well known to voters. In a recent Suffolk University poll, 75 percent of voters had an opinion of Brown, and nearly 90 percent had an opinion of Shaheen. By comparison, just over half had an opinion of former Sen. Bob Smith (R-N.H.), another possible rival to Shaheen, with 24 percent saying they'd never heard of him.
As FiveThirtyEight's Harry Enten notes, Shaheen's favorable ratings aren't exactly those of a vulnerable incumbent, while Brown's aren't those of a well-liked challenger. Rasmussen gives her a net 17-point favorable rating, compared to -2 for Brown; Suffolk puts her at +16 and Brown at -10.
Rasmussen surveyed 750 likely voters on March 12 and 13, while ARG surveyed 533 registered voters between March 13 and 16.