Some top Republicans at odds with Sen. John McCain on core conservative issues say privately that the party's 2008 presidential nomination is "his to lose." They cite the Arizona senator's head start in fundraising, a primary calendar that is shaping up in his favor and a growing belief that he enjoys the tacit support of President Bush. In state after state, Mr. McCain has been passing out money to Republican candidates for other offices, to state party organizations and even to Republican county chairmen. Now, one of the most widely respected conservatives in the country says he is ready to...