The Republicans fought very hard (and won) to have the lines for the Congressional districts redrawn fairly recently to have larger conservative majorities by (I would guess) splitting up the more liberal areas to have fewer of them per district. Before they did that, Edwards won by pretty comfortable margins as far as I can tell. After they redrew the districts it got harder and he won by narrower and narrower margins-- he won in 2008 pretty much riding on Obama enthusiasm, and there's not much of that left this year.

So that's what's up with our district.