If affirmative action in the United States has you confused, imagine what it's like in Brazil, where everything is muddier. Half a millennium of mingling by Africans, Europeans and Indians gave this New World nation a hundred faces and more colors than Crayola. (One famous national census turned up 136 terms by which Brazilians classified their complexion, from "dawn white" to "cinnamon.") The record-keepers, hoping to tidy things up, reduced the official lexicon of racial types to just five: white, oriental, indigenous, black and pardo (brown). But to this day, most Brazilians simply shrug and say they are a mixed-blooded people.

Blurry as that seems, this fluid self-image has been key to the country's identity. Now, thanks to an aggressive new brand of racial politics, the picture is about to change.