I don't like it, either, but if Rudy is the nominee, I really don't see another way out of the mess. The Republican Party cannot abandon the social conservatives so completely by nominating someone completely antithetical to their views (at least Romney pays them some lip service). If so, they will go back to the status they had during the New Deal-Great Society days, when the only person we could elect as President was a general who was allowed to win a war. It will take a generation or more to rebuild this party, and the unborn will have been forever abandoned by that point.
What's the sense in voting for the guy with the (R) next to his name, if the brand no longer means anything?
The GOP would also be abandoning small government conservatives by nominating Giuliani. There may be a few who care only about taxes who would still support him. However, most small-l libertarian types care about the overall size and intrusiveness of the federal government, not just about taxes. For the latter group, Giuliani would be a disaster.
So, the current leader in the polls represents an abandonment of 2/3 of the Reagan coalition (and IMO, his national security record doesn’t merit the support of the defense hawks, either). As the old curse goes, we live in interesting times.