Maybe Tennessee because all the Republicans are in the Far East while the Democrats are a bit more evenly dispersed everywhere else generally.
I actually think Tennessee has an R bias because Dems really only get any votes from 4 places. Although they’re spread out throughout the state, Memphis and Chattanooga are both in far corners of the state while Nashville and Knoxville are surrounded in every direction by huge R margins. For example, 538 D gerrymander still produces a 7-2 split and the most competitive D opportunity seat has to involve Nashville with the eastern cities since you can’t get a competitive seat out of eastern Tennessee alone.
I think this Dem clustering applies much the same to Maryland which is mentioned earlier in the thread. It leans hard D due to gerrymandering but I think R’s are actually spaced efficiently for how few of them exist there
