[theluketaylor]

The system here only works because the Canada Health Act requires every province to have a universal health insurer for provincial residents and mandates each province accept the insurance of the others. If only Ontario had a provincial insurer or the provinces didn't have to accept each other's programs there would be a ton of game theory style manipulation.

Any state trying to implement a single payer system would get crushed as tons of individuals and even other states tried to milk the system (like putting homeless people on a bus with a one way ticket).

States would need a "suicide pact" of sorts to ensure a bunch of states made the leap at the same time. There actually is such a plan to subvert the electoral college to ensure the popular vote winner always wins the presidency, but that's a relatively simple pact around single law. Health care laws a incredibly complex and rather than try some kind of weird multi-state pact you're better off fighting for a national law.