Sen. Scott Brown (R-Mass.) now leads Democrat Elizabeth Warren by 2 percentage points in a new Boston Globe poll, a reversal of the same poll's September numbers, which showed Warren ahead.
The new poll gives Brown 45 percent support to Warren's 43, a statistical tie within the survey's 4-point margin of error, just over a week from Election Day. In September's Globe poll, Warren held a 5-percentage-point lead over Brown, 43-38.
When undecided voters were asked to choose one candidate or the other, the race is a dead heat, with 47 percent backing each.
Warren might also be suffering from President Obama's shrinking coattails in the state, with the new poll showing a 13-percentage-point drop in support for the president from September.
The news that Obama has seen a decline in support in one of his strongest states comes as the president faces tightening poll numbers in a number of other states that originally seemed to be trending in his favor, including Pennsylvania and Minnesota.
In Massachusetts, however, it seemed until this poll that Obama could only boost Warren, as he's consistently posted a double-digit lead on Mitt Romney. Warren has, in fact, worked to tie herself to the president, framing herself as a strong supporter of his policies and even receiving his endorsement earlier this month.
Though she's seen a drop in support in this new poll, it's the first since early October that puts her behind Brown, and until now, a number of nonpartisan political handicappers — including The Hill — had given Warren an advantage, moving the race from a toss-up to "lean Democratic."
The two will meet for their final debate on Tuesday night, a face-off that could be pivotal in deciding one of the closest races in the nation.
The Boston Globe poll was conducted by the University of New Hampshire among 583 likely voters and has a margin of error of plus or minus 4.1 percentage points.
--This story was updated at 1:29 p.m.