Who would be considered the largest party coalition members? The so called base if you will, of republicans? I don’t mean the base of over 30 years ago, but the base now in 2012?
There are dozens of different groups and movements within the Republican coalition ~ however, it's not so much the base that's a problem, but a group that is not part of the base ~ we've ended up calling it the GOP-e on FR. They are at most 15% if you count all their hangers-on and supplicants.