Actually they should rule the entire civil rights legislation from the 1960s is unconstitutional.
It is one thing to prevent governments from discriminating but it is another to restrict citizens.
If the government can tell you who you can and cannot associate or do business with then you are not a free citizen.
One reason race relations have not improved is because the government got involved. The open market place would have resolved many issues without the underlying resentment or the belief only the government can create fairness.