That's an easy one. A 1993 Supreme Court case, Wisconsin v. Mitchell, which established that hate crime legislation did not violate First and Fourteenth Amendment protections was a case where a group of black teens attacked a white teen based solely on his race. The black teens were charged with, among other things, violation of Wisconsin's hate crime laws. They were convicted and the Supreme Court upheld it.
And yet Wisconsin found the ruling unconstitutional agreeeing that the hate crime law violated the black teens rights