Political Memo; Bloomberg's Challenge: Be a '93 Giuliani, but in '01
Political Memo contends that while Michael R Bloomberg is attempting to model his candidacy on Mayor Rudolph Giuliani's 1993 campaign, city is very different politically, with more immigrants, smaller pool of old-line Democrats who supported Giuliani, and fewer partisan considerations; Democratic candidates base their campaigns on competence and experience, and Bloomberg focuses on his record as entrepreneur; with no compelling issues, voters may reject or ignore him (M)