The breakdown is along the lines of the old Reagan coalition of social and fiscal conservatives, that he created back in the late 1970`s and had been so successful for the GOP over the last 30 years. Check out this great speech Reagan gave to the 4TH Annaul CPAC Convention, Feb 6 2007, called The New Republican party.
Before Reagan came along and joined these two conservative factions, the Rockefeller Republicans ruled the GOP. The Rockefeller wing of the GOP died 30 years ago and Reagan killed it.
It seems to be resurrecting itself. :-(