Former New York Mayor Rudolph Giuliani has the record, reputation and travel schedule of a serious White House contender. But it will not be easy turning "America's Mayor" into America's president. Riding high on the acclaim for his leadership in New York after the September 11 attacks, Giuliani is a huge draw on the Republican fund-raising circuit and one of the party's most popular figures. Some opinion polls show him joining Arizona Sen. John McCain (news, bio, voting record) at the top of a crowded field of potential Republican candidates to succeed President George W. Bush in 2008. But Giuliani's...