I strongly second Philip Klein's arguments in favor of Rudy Giuliani being elected President in 2008.
It is true that Giuliani is quite liberal on certain hot-button social issues, in particular, abortion and gay rights. However, while these issue are important (and I disagree with Giuliani's positions on them), they are peripheral issues compared to crime and welfare -- on all of which Giuliani offered strong, conservative, outspoken leadership during his eight years as Mayor of New York City (a city bigger than all but 11 states).
Giuliani literally saved New York City by releasing it from the death grip of terrible crime and rampant welfare. This was a greater accomplishment than almost anything any modern American politician, at any level of government, has accomplished -- and, frankly, much greater than anything Senator McCain, Senator Frist, Senator Allen, Governor Romney, and the lesser Republican hopefuls have ever accomplished in their political careers.
And let's not forget Giuliani's outspoken opposition to the vulgar, sacrilegious "art" displayed at the Brooklyn art museum. While Giuliani may hold libertarian views on many issues, at his core he is a traditional, "middle-class" American. And as Mayor he worked extremely hard to make the middle-class vision of the American Dream a reality in New York City. His middle-class vision, coupled with his steely determination (even arrogance) in the face of elitist liberal opposition (which he suffered as much as President Bush), is exactly what we need in our next President.