Suggest a feasible center-right candidate, by all means. Vote for him in the primary - knock yourself out.
But threats to defect, or go third-party, if Giuliani does win the nomination, are truly idiotic. That is all I am saying.
No, what is truly idiotic is pushing someone from the far, far left of the GOP as its presidential nominee, given the disasterous electoral history for the GOP when the party drifts leftwards.