Pawlenty is pro-amnesty and a believer in manmade global warming. Using your logic, if Giuliani can get elected in NYC, he can get elected throughout America.
Pawlenty is quite a bit more conservative than Giuliani, and also has a spotless personal life.
Pawlenty has a likability that will persuade independents and moderates to vote for him.
Sarah Palin gains enthusiasm only among the most conservative, people who would be voting Republican anyway. Palin might make a good VP pick if she does well in the Presidential primaries but can’t defeat Pawlenty.