In one, from Western New England University, Democrat Elizabeth WarrenElizabeth Ann WarrenWarren: Trump is a 'racist bully' Poll: Oprah would outperform Warren, Harris against Trump in California Democrats continue to dismiss positive impacts of tax reform MORE leads Sen. Scott Brown by 5 points, with 50 percent support to his 45 percent support. That largely mirrors its last poll, conducted in early September, that gave Warren the same level of support and Brown just 1 point less.

But another survey, from local news station WBUR, is the first in now five consecutive polls to give Brown a lead. That poll shows him ahead with 47 percent support to Warren's 43 percent. It's a reversal from the last WBUR poll, just a week prior, that gave Warren a 2-point lead over Brown with 46 percent support.

The latter poll was conducted following the second debate between the two candidates, while the first poll, which gave Warren the lead, was conducted both before and after the second debate, perhaps indicating that Brown received a slight boost from his performance there.

But two debates still remain, and neither candidate is likely to forfeit any advantage they can gain from the face-to-face forums that have thus far been fruitful opportunities for each to hammer the other on policy and personal issues. 

The Western New England poll was conducted among 440 likely voters from Sept 28-Oct. 4, and has a margin of error of 4.7 percentage points. The WBUR poll was conducted among 501 likely voters from Oct. 5-7, and has a margin of error of 4.4 percentage points.