Grove Insight for EMILY's List (9/8-10, likely voters):
Betsy Markey (D): 47
Marilyn Musgrave (R-inc): 38
(MoE: ±4.9%)
This is the third poll we've seen showing Musgrave behind; an internal Markey poll from May had Musgrave trailing by seven, and a recent SurveyUSA poll confirmed that spread. In fact, the only poll we've seen of this race with Musgrave ahead was an internal poll conducted for her campaign in March that pegged her lead at five points.
One thing worth noting about the poll, though: It was conducted before a recent kerfluffle over highly charged ads by Musgrave alleging ethics violations by Markey during her time spent as an aide to Sen. Ken Salazar. There's also this:
However, the partisan edge among self-identified Republicans in the poll is smaller than the party's advantage in voter registration numbers and historic turnout trends, suggesting GOP voters might be under-represented in the poll. The Republican identification edge over Democrats was 9 points in the poll, compared to 13 points in current registration numbers in the 4th Congressional District and 17 points in the 2004 and 2006 election turnout numbers.
