President Obama highlighted Mitt Romney's "47%" gaffe during his appearance on "The Late Show with David Letterman." In response, Obama told Letterman: "One of the things I've learned as president is you represent the entire country. My expectation is if you want to be president, you've got to work for everybody, not just for some. When I won in 2008, 47 percent of people who voted, voted for John McCain. They didn't vote for me. And what I said on election night was, even though you didn't vote for me, I hear your voices and I'm going to work hard as I can to be your president."