ONLY a few months ago, conventional wisdom throughout much of the political world was that former New York Mayor Rudy Giuliani might make a competitive Republican candidate for president in a general election, but he could never win his party's nomination because conservative primary voters would reject him. Now, suddenly, that wisdom seems to have shifted, and as Giuliani trouped through California last week, he was wowing conservatives with his charisma, his gift for sounding spontaneous on the stump and his call for bold national leadership. "Rudy" - as he is known everywhere - has already been accepted as one...