WASHINGTON The Senate sidetracked sweeping immigration legislation Friday, leaving in doubt prospects for passing a bill offering the hope of citizenship to millions of men, women and children living in the United States illegally. A carefully crafted compromise that supporters had claimed could win an overwhelming majority received only 38 of the 60 votes necessary to protect it from weakening amendments by opponents. Republicans were united in the 38-60 parliamentary vote but Democrats, who have insisted on no amendments, lost six votes from their members. Democrats and Republicans had been blaming each other Friday for problems stalling the progress of...