OK, here's the summary of the story in the OP.
The author and her husband attempted to rent booth space at the NAACP convention. The NAACP declined to rent them that space. One possible reason is that the author is repeatedly and vocally critical of the NAACP.
So, you tell me. Does the "blacklisting" of a single conservative black author constitute discrimination against black conservatives generally? Can there be justification for an organisation to refuse to rent booth space at its convention to a person who has made a career of attacking that organisation?
If the Republican Party refuses to allow Noam Chomsky (a famous leftist and anti-Republican writer) to speak at its convention, is it being discriminatory?