States learning from each other is good, but there's no reason to restrict that learning to other states within the same Union (which for cultural and numerical

States learning from each other is good, but there's no reason to restrict that learning to other states within the same Union (which for cultural and numerical reasons are more homogenous than the total population of all states). If the United States looks only inwards, however, there's nobody left to learn from in terms of how to run a Union, since there is only one United States, and its powers and responsibilities are (because of federalism) quite different from those of the states.