While the 5th district, which is now open due to Rep. Chris MurphyChristopher (Chris) Scott MurphyOvernight Health Care — Presented by the Association of American Medical Colleges — Governors criticize Trump move on pre-existing conditions Bipartisan group of senators asks FDA to examine drug shortages Trump faces Father’s Day pleas to end separations of migrant families MORE's (D) run for Senate, leans Democratic — as does the rest of the state — it's the likeliest opportunity for a Republican pickup there. Roraback is a more centrist candidate, and he's reached the third level of the National Republican Congressional Committee's Young Guns program, which grooms up-and-coming Republican House candidates.

But Esty, too, is backed by the Democratic establishment, having been named as one of the DCCC's Red to Blue candidates — an indication it believes she's a strong contender — and EMILY's List, which backs female Democrats.

The poll was conducted among 400 likely voters in the district from Sept. 3-4, and has a margin of error of plus or minus 4.9 percentage points.