Larison gets into the mindset behind Mitt's "Obama apologizes for America" nonsense:
This rhetoric about apologies and other conservatives’ charges that Obama didn’t believe in American exceptionalism were never meant to refer to anything that Obama had actually done. Instead, they were opportunities for the people making these charges to wrap themselves in the mantle of American nationalism, define belief in American exceptionalism in such a way that it could only apply to people who agreed with them, and to impute anti-Americanism to anyone else. The entire exercise is clearly fraudulent, but it is also one that many Republicans find quite satisfying.
And have you noticed Romney's creepy slogan: "Believe In America"? Ugh.