Dear Jameison,
"Now Guiliani has been relatively very quite since he stopped being mayor,..."
That's not true. Mr. Giuliani has been remarkably active, showing up in places where they have early primaries, campaigning for Republican candidates, etc. He may be flying a little low under the national radar, but he already has so much name recognition that he doesn't need anymore.
He is, however, doing what smart presidential candidates do in the spring of the mid-term elections - he's trying to connect with local Republicans, and with individual Republican office-holders and candidates. He is working hard at it, and not without some success.
However, in the final analysis, he is a party-splitter. The social conservatives are the single largest part of the Republican coalition, but the hard-core social conservatives are not a majority of the party by any stretch. The rest of the party could force Mr. Giuliani on social conservatives. In fact, there appear to be folks here at FR who would love nothing better, to force a showdown isolating social conservatives from the rest of the party. They amuse themselves by fantasizing how good it would be for the party to get rid of social conservatives, and how Mr. Giuliani would realign the Republican Party, effectively silencing the voice of us evil social conservatives once and for all.
It's an interesting fantasy. It's even theoretically possible that it could happen, although I don't really think that Mr. Giuliani's the fellow to get it done.
However, the alternative, and more likely, reality is that after sundering social conservatives from the party, Mr. Giuliani would go on to be the first Republican presidential candidate since 1976 to be defeated by a Democrat while giving the Democrat an actual majority of the popular vote.
sitetest