When Colin Powell flirted with a presidential campaign in 1995 as a Republican, not one single Democrat questioned his citizenship. Your thought experiment is interesting, but I think that because more liberals are intellectuals, any initial questions about a Republican Obama’s citizenship would have been quashed early and hard. Most conservatives have a more emotional response, which is why they can be afraid that Obama wasn’t born here even after the evidence is provided.

Although race is certainly a factor here, I would hesitate to call this racism however, but would rather refer to it as the politics of difference, where race is indeed a factor, but only one among many. Many Americans have a fear and distrust of those that are not like them, certainly do not want to acknowledge that the United States is not simply a “white” country. Yet as a thought experiment, I wonder how such a matter would have been dealt with if Obama were in fact Republican. Would a “birther movement” emerge from from the Left? If so, could we call it racism then? Indeed, the ways that “otherness” is constructed are many, race being only one marker; ideology and culture are also very important factors in this.