MANCHESTER, N.H. — As they ponder how to win back the White House, many Democrats fear that the early front-runner for their party's 2008 presidential nomination, Sen. Hillary Rodham Clinton, carries so much baggage that she would drag the party down to defeat. Many support her, to be sure, and even more admire her. Polls confirm she has the early edge over other potential rivals. Party insiders think she'll enter the race soon after her expected re-election as a New York senator later this year, with a $50 million head start on fundraising toward 2008. But ominous signs abound, and...