I remember following the 2008 republican and democratic races I don't remember any of the front runners being treated as bad as romney, by his own people. Wow and romney says everyone will unite. Really? Your main rival is saying on national tv he rather have obama for a 2nd term. So that says obama is not bad afterall. And your advisor goes on tv saying crazy things in the same week. Obama is one lucky guy. I hope santorum drag this race out because everyday he makes it better.
Besides what was already mentioned, the Hillary campaign started the birther and "Obama is a Muslim" chain emails (as well as running one of the most obvious dog-whistle campaigns ever - "I'm the candidate of hard-working white people," "Jesse Jackson did well too," "If Obama was a white man, he would not be in this position."). Jerry Brown refused to endorse Clinton in 1992. Nelson Rockefeller spent his convention speech in 1964 attacking Goldwater.