MORE ON TURNOUT

Other people have remarked on the relatively disappointing GOP primary turnout and Nate Silver did the basic research:

South Carolina may be home to more reactionary extremists because DeMint is perhaps the biggest rightwing wacko in the Senate and that could account for the higher turnout. Michael P. McDonald dug into the Florida results and found that Newt won the districts that had a higher turnout compared to 2008.

From this we can draw a provisional conclusion: right now, there aren't that many Baggers in the GOP.