> relatively little friction if you decide to move to a state that better reflects them.

Yes, moving is possible, and easier than switching countries. But the biggest strength of the U.S. is not that people can move, but that the blast radius is contained. The strength is being able to think later "I'm glad we didn't try that everywhere at once." The strength is being able to experiment, not necessarily have states aligned to with all there residents needs within a certain threshold.