Can we just call it like it is on this whole Birther thing!? Republicans often speak in code so let me just break this down: what Birthers are really saying is, 'a black man can never be a real American.'
That's why they are so completely unhinged. Obama's election, in their minds, changed the definition of what it means to be an American and they are furious at having their white privilege eroded. First they claimed Obama was Muslim. Then they held protests where they told Obama to suck their balls (that's why even as they were being ridiculed they didn't change the Tea Bagging message -- that was exactly what they wanted to be saying). Now they're saying 'he can't possibly be American' and manufacturing the birth certificate nonsense.
In each case, prominent racists like Rush Limbaugh, Lou Dobbs, and Bill O'Reilly are the ones promoting these memes. The particular form of outrage they come up with each month (Muslim, Rev. Wright, Tea Bagging, birth certificate, etc.) does not actually matter -- it is just packaging to carry their core message that only white people are real Americans. But they can't come right out and say that without facing censure so instead they speak in code and try to pass this vile nonsense off as legitimate debate.
Update #1: Jon Stewart completely smacks down the Birthers.