One criticism of Nia-Malika Henderson's article on Obama's "dogwhistling" is that many of the cultural markers that Henderson takes as black are either generational, or things that whites understand. The first thing that should be said is that blacks also heard Reagan's dogwhistles--it's not like we didn't know what he meant by "states rights." But more to the point, we went through this a few months back when Obama gave his wife a pound after he secured the nomination. The argument, again, was that this wasn't anything "black" because "everyone" does it. I think this argument originates from the idea that black is the perfect and exact opposite of white. Historically whiteness has meant exclusion (though this may be changing) and so when whites hear that something is labeled "black," they may think "not for me."
But of course blackness isn't the perfect opposite of whiteness--black is not simply a racial identity, it's also an ethnic identity. So, in much the same way that Jews are, in this country, racially white and ethnically Jewish, blacks are "racially" black and--in the main--ethnically "African-American." This can get hazy when we start factoring in diaspora influences, but the point is that blackness, for black people, isn't a matter of being born, simply with a certain skin color. Indeed, in some cases, it isn't that at all. It's about practices--the way we eat, the way we live, the way we walk. It doesn't mean that all black people participate in this, nor does it mean white people can't participate in it.