Some Democrats are beginning to doubt Sen. Hillary Rodham Clinton's electability in 2008 and are saying so publicly for the first time. The New York liberal, who is far ahead of her rivals for the Democratic nomination in all the polls, is the most polarizing figure in American politics. Half the voters polled say they would support her if, as expected, she becomes a candidate, but the other half says they couldn't vote for her under any circumstances. Her inability to reach out to more moderate voters worries Democrats who think '08 is their year to win back the White...