 Since Congress cannot directly force states to legislate according to their scheme, and since Congress likewise cannot force them to take title to radioactive waste, O'Connor reasoned that Congress cannot force States to choose between the two.Such coercion would be counter to the federalist structure of government in which a "core of state sovereignty" is enshrined in the Tenth Amendment.The Court found the "take title" provision to be severable and, noting the seriousness of the "pressing national problem" being addressed, allowed the remainder of the Act to survive.