The race is still in the early stages, as both faced competitive primaries that came to a close just a few weeks back. But Democrats and Republicans are both enthusiastic about their chances in the new district; though it leans Democratic, Republicans believe Sinema could be too liberal to win.

President Obama leads Mitt Romney by 6 percentage points in the district, which he would have won by 4 points in 2008, according to the polling memo.

The survey was conducted among 400 likely voters from Sept. 8-10, and has a margin of error of 4.9 percentage points.