"If such a tragic tarnishing of the reputation could happen to a fresh-faced reformer like Obama, it could happen to anybody. And, in fact, it has - at least to anybody who has happened to attain the Democratic presidential nomination at any point over the last five election cycles. John Kerry, as everybody remembers, came to be defined almost exclusively as a flip-flopper. (A 2004 Wall Street Journal news article described him as 'a politician with a troublesome reputation for trying to have it both ways.')... It was true: Voters didn't trust Clinton - or Gore, or Kerry. In all of those elections, polls showed the Democratic nominee scoring higher on most of the issues, but the Republican nominee scoring higher on honesty and other personal qualities. Either this is because the Democratic Party keeps nominating weasels for president, time and time again, or else there's something systemic that makes Republicans (and the press) portray them as such. I'm going with explanation number two."