There is quite a difference, Burt, in voting for the lesser of two evils and voting a leftist to head the only major right-of-center party in the US. Voting for Rudy in the general is akin to losing a war to win a single battle. It would signal the end of the Republican party as we know it and stifle the progress of the conservative movement for years to come.
I, for one, will not take part in the suicide of a movement that I believe in. If that means Hillary is elected, so be it. The alternative, which is having nobody to fight the ongoing war against liberalism, is much worse than four years of Hillary.