Interesting E.J. Dionne column on the implications of a doctrinally rigid GOP upon the Republican presidential candidate field in 2010 here.
I believe he has a strong point. I have been fascinated to note that of all the candidates declared thus far, Newt Gingrich (not, I must admit, my favorite politician) has been most willing to step out on a limb with his argument that the Republican-proposed overhaul of Medicare is just as radical as anything proposed by the Obama administration's health care policy.
Ideological rigidity is not a problem limited to one party. Both Democrats and Republicans have been (and are being) hurt by their reluctance to topple the straw men (straw people?) constructed on both sides of the political battlefield. Indeed, I almost typed "political spectrum" only to reflect that I fear we do not have a spectrum at the moment so much as two poles, separated by a chasm of don't-go-there... and it is in the more complicated terrain of the middle where we will find any true solutions to be had. There are some things upon which no compromise is possible, but most of the political problems we face at present just aren't among them.