Their most important function in the real world is to simply serve as a hedge or insurance policy against bad outcomes. But lots of critics of the free market from the left and increasingly the right, have a point: Free markets do not guarantee optimal outcomes. But the more dedicated society is to free markets, the higher the evidentiary burden to grant an exception. If you believe in elections only so long as your team wins, you don’t really believe in elections. Being for something like states’ rights when the other party is in power but federal supremacy when your party is in power is not really a principle.