I'm going to go with "this is a fringe thing". I will say that the Republicans should have a talk about their racist fringe element, and take real steps to show that this sort of thing is not acceptable in American politics. Here's a suggestion - Mitt Romney could make this statement:
"There are many reasons to vote against Barack Obama. His economic policy has failed the country, he has engaged in rampant spending, [insert a few more standard Republican talking points]. However, his race is NOT a reason to vote against him. If you're voting against Barack Obama just because he's African-American, then I don't even want your vote."