READ HIS LISP. Giuliani's 9/11 message, and his recent invocations of Reagan, having failed to move the needle, he shifts to a classic Republican Presidential gambit, and in a big way: from his first day in office, his new ad promises, he'll "cut taxes by trillions of dollars." The ad claims that as mayor Giuliani "delivered more tax relief than all the other Republicans combined" and adds he's "gotten it done where it was even more difficult to do it than in Washington" -- that is, in the liberal hellhole New York City.