Brown leads every potential Democratic challenger by anywhere from four to 18 percentage points and comes out ahead of every Republican contender tested as well.

Most Democrats and Republicans have relatively low name identification in the state, however, so the landscape of the race could shift closer to the election when candidates begin to announce.

Brown, who was defeated by Sen. Elizabeth WarrenElizabeth Ann WarrenOvernight Regulation: Net neutrality supporters predict tough court battle | Watchdog to investigate EPA chief's meeting with industry group | Ex-Volkswagen exec gets 7 years for emissions cheating Overnight Tech: Net neutrality supporters predict tough court fight | Warren backs bid to block AT&T, Time Warner merger | NC county refuses to pay ransom to hackers Avalanche of Democratic senators say Franken should resign MORE (D) in 2012, hasn't been coy about his interest in both the Massachusetts gubernatorial race and the New Hampshire Senate race.

Though the latter looks less probable, as he'd have to contend with attacks on his Massachusetts residency, Brown has made five stops around the Granite State over the past two months, stoking speculation about a potential 2014 run.

This new poll could give him reason to forego a New Hampshire run in favor of a Massachusetts gubernatorial run, as a PPP poll of the New Hampshire landscape put him 11 percentage points behind Shaheen in a potential matchup.

The poll was conducted from May 1-2 among 1,539 Massachusetts voters and has a margin of error of plus or minus 2.5 percentage points.