“If Obama is not truly American, then America has still never had a black president.”...
.. Romney is not himself a birther. He was engaging in ironic post-birtherism—showing solidarity with birthers by making a humorous remark that can be plausibly denied as a joke later. This is a necessary device for a Republican politician who wants to rile up the base without seeming like a lunatic, because the belief that President Barack Obama was not born in the United States is still held by nearly half of self-identified Republicans even after the very public release of the president’s birth certificate. Birtherism remains the most frank and widespread evidence of racial animus among some of the president’s critics. As Ta-Nehisi Coates writes in The Atlantic this month, the birthers, strapped in their waxen wings, aim for nothing less than the sun: “If Obama is not truly American, then America has still never had a black president.”...
http://www.theatlantic.com/magazine/archive/2012/09/fear-of-a-black-president/309064/?single_page=true
I suspect many Republicans who continue to subscribe to the birther lunacy do so because it bothers liberals and because it’s an act of symbolic defiance of a president they dislike. The problem with birtherism, however, is that the underlying assumptions driving it have always been broader than the president. Birtherism is more than just a conspiracy theory about the president’s birth. Its underlying principle is a rejection of American racial pluralism. The refusal to believe—in the face of all evidence to the contrary—that Obama is an American reads to many as saying black people don’t really count as American unless they talk like Herman Cain or Allen West.
That’s the problem with Romney’s “joke,” too. It falls into a long list of remarks that suggest an emotional myopia based on an extremely sheltered life experience. It comes across as gloating about the fact that, as a rich white man born into a wealthy and powerful family, Romney has rarely been subject to the kind of racist or sexist assumptions that clog the daily lives of millions of Americans. Romney might as well joke that he’s never been mistaken for a waiter in a restaurant or a clerk in a retail store, or that he’s never been selected for extra screening at an airport or randomly told to empty his pockets by the NYPD. The reason Romney doesn’t have to show the country his papers isn’t because everyone knows he was born in Michigan. It’s because whiteness remains unquestionably “American” for some people in a way blackness does not. That should not be a point of pride for Romney; it should be a matter of anger and disappointment.
more:
http://www.motherjones.com/mojo/2012/08/romney-birtherism-joke-michigan