That would be Mary Landrieu, who said that part of the hostility against Obama in the South had its roots in racism, that’s the truth bit, and now she has refused to apologize for speaking the truth:

Louisiana Senator Mary Landrieu made conservative heads explode by stating a truth, that the South has not always been the friendliest place go African-Americans and to women. Landrieu’s campaign put out a press release standing by her comments.

This is a level of guts and honesty that I would never have expected of her.