 § 1981 (popularly known as the "Ku Klux Klan Act") indicated that the Act was not designed to prohibit private racial discrimination but only state-sponsored racial discrimination (as had been held in the "Civil Rights Cases" of 1883).White was concerned about the potential far-reaching impact of holding private racial discrimination illegal, which if taken to its logical conclusion might ban many varied forms of voluntary self-segregation, including social and advocacy groups that limited their membership to blacks