1. Even though his name was scarcely mentioned (and this makes sense for Republicans): George W. Bush. People realized that not only did Obama inherit a shitstorm, Romney was advocating a return to the policies which caused it.
2. Romney's total lack character. What do you want to hear? Because I'll tell you that. No, I didn't just state the exact opposite when speaking to a different group of people.
3. Out-of-touchedness, crystallized by the 47% remarks. And NOT because he's rich, people were OK with that. Rather, because he doesn't know what it's like to live paycehck-to-paycheck.