If the government followed the constituion this wouldn't be problems: 1. Marijuana would never have been illegal at the federal level because an amendment wasn't passed. 2. Healthcare and any other federal welfare policies could be ennacted by passing an amendment.

If there isn't broad consensus across the country to pass an amendment then states can do it independently. There is no reason a state can't have single payer healthcare, except that they don't want to pay for it and want to just add the cost to the national debt.