It seems to be that the US ends up with the worst of both systems. States are not separate countries so they can not deny access like another country would deny a rapist from immigrating but they are also not unified so they can't take any collective action.
Seems to be the core of the covid situation too. There is no unified plan and guidance but states doing well can't shut borders to continue doing well.
> There is no unified plan and guidance but states doing well can't shut borders to continue doing well.
Can't or won't? If California can get away with its agricultural checkpoints without running afoul of e.g. the Commerce Clause, then it seems like restricting interstate border crossings is at least hypothetically possible.
In practice, it's pretty trivial to bypass those checkpoints if you really want to smuggle produce into the state (e.g. the I-80 checkpoint, where you can take the Hirschdale Road exit and follow Glenshire Drive to 287, then get right back on I-80). I highly doubt COVID checkpoints would be any harder to bypass.
Seems to be the core of the covid situation too. There is no unified plan and guidance but states doing well can't shut borders to continue doing well.