Here's Mitt Romney in Michigan, talking to a group of voters:

"Now I love being home in this place where Ann and I were raised, where both of us were born. Ann was born in Henry Ford Hospital. I was born in Harper Hospital," Romney said, continuing: "No one's ever asked to see my birth certificate. They know that this is the place that we were born and raised."

The crowd cheered in response.

Ha, ha, "Everyone knows I'm a real American, due to my white skin! No one would ever ask to see my papers, because I am white!" [Crowd cheers.]

Theoretically this is too obviously racist to count as a "dog whistle," and yet people seem to not notice that Romney is basically pointing at his skin and winking:

The "dog on roof" stuff is jokes about something that Mitt Romney actually did. The birther stuff is made-up paranoid racist conspiracy theories attacking the very legitimacy of Obama's presidency. They are not the same "stuff." And anyway: Donald Trump and Sheriff Joe Arpaio — avowed birthers, both of them — are speaking at the Republican national convention next week. Neither Gail Collins nor Seamus the dog have been invited to give addresses to the DNC, to the best of my knowledge.

On the other hand maybe Romney would rather spend a day with the cable news networks talking about this and not about shady Bain deals, taxes, Todd Akin, abortion, or medicare?

Either way Mitt Romney could probably win a bunch of states on a platform of "being white." And in fact he is basically running on that platform in several states.