It is Congress, the Court actually turned down two major AWB/mag capacity cases in the last few days. I suspect the unanimity is because the plain language of the Civil Rights Act does prohibit reverse discrimination, and the liberals would have to go out on a very long limb to defend it (original intent notwithstanding). I would suspect conservative justices granted the petition and the liberals went along because any dissent would just blatantly support reverse discrimination and that would be worse than if they had denied the case writ in the first place, which they would have.