Antonio Brown, presumably. “All that is cap,” is probably supposed to be "all that is Kaep".
But yes, as a white person I have no opinion on this that anybody should ever listen to, but it's obvious to everybody that Kaepernick is about as black as your neighborhood white guy is. Same with lots of people who cash in on their "blackness". Megastar musician Drake comes to mind. These are the sorts of "black" people your neighborhood progressive white women would love to be dear, dear friends with.