Looking at other districts in other states, Mike McIntyre's in NC went 39.9% Obama in 2012 and he retired because he didn't think he could win it again. Nick Rahall's in WV went 42.3% Obama in 2008 but only 32.8% Obama in 2012, and he's in the fight of his life this year. Jim Matheson's went 40.9% Obama in 2008 but only 30.2% Obama in 2012, and he retired.
Looking at the context, it looks like it's in the range where Democrats just don't win those districts anymore. I think we could beat Broun statewide, but if we can't, we certainly couldn't beat him in a district that looks almost 10 points more Republican than the state of Georgia.