It's the South:
The WSJ Real Time Economics blog has posted the letters for and against the health care reform bill winding through Congress. The most interesting thing about the lists of signatories is the geographical divide. It was so interesting, I did a fast tabulation (so, don't quote me on it), and what one finds is that of the list in favor, only 2 of 41 economists are affiliated with institutions in the South (defined using the most restrictive definition in this Wikipedia page -- so to be completely accurate, I haven't used the actual Mason-Dixon line). Of the 131 signatories to the against letter, 40 are affiliated with institutions in the South, i.e., essentially 30% of the total.