For months New Jersey Republicans had smelled blood in the water and were lining up to take on Gov. James E. McGreevey. A state assemblyman, a state senator, a businessman, a small town mayor and perhaps a federal prosecutor were all considering the prospect of challenging the Democratic incumbent. Mr. McGreevey had been viewed as vulnerable because of a series of investigations involving top aides, a major fund-raiser and his leading campaign contributor. And it seemed that a state that had turned to the Democratic column - with two Democratic United States senators, and both houses of the State Legislature...