I think it is possible that in the future this Supreme Court may find that same sex marriages and mixed race marriages are not constitutional rights, the same as abortion isn't. They might be civil rights that Congress can specify as legal and authorized, but what Congress can create can also be changed or deleted by a future Congress. And of course if in time the Court's composition changes to be more progressive then who knows what will happen. I'm sure there will be legal challenges between individuals and the states vs Congress, and that which is legal or illegal now can change down the road. Not just these issues either.