I don't really what Rex said. The issue is about not being told who businesses may hire. Comparing that to an organization founded to support a certain group of people is irrelevant. That's the purpose of groups and no one is stopping you or Rex from forming a group to support the views of "Left-handed Fisherman" if you so desire. There's no law that says you may not start a business or group to support only one race, religion, etc. There is a law passed that states all people must be treated equally and that you may not use race as a means to discriminate.

Comparing the Civil Rights Act to whom these groups may include in their membership is relevant.