What is meant by "post-racial"?
A post-racial society is one where racial issues don't exist.
It's commonly used by people (mostly conservatives) in reference to the US. The argument is that because all people can vote, own businesses, no one is enslaved, et cetera, there cannot possibly be any racism in America. People who believe in this post-racial theory often cite the fact that we very recently had a black president as further evidence. To those experiencing the racism in America, these claims seem patently ridiculous.