Mitt Romney on Thursday night praised President Obama for killing Osama bin Laden, even while giving him an overall “F” when grading his term. “I’m sure he has,” Romney told CBS News, when asked whether Obama had done anything well. “I appreciated, for instance, the decision he made to go after Osama bin Laden and to make sure he was executed.” When asked what grade he would give the incumbent he is trying to unseat, he said, “Oh, an F. “