These two cases illustrate federalism because they show that there are different powers that are given to the national government and to the state government. Neither level of government can define its own powers. Instead, the powers are doled out by the Constitution. In these cases, the Supreme Court was deciding which powers had been given to which level of government. It had to decide whether the states are allowed to legislate about immigration the way Arizona did. It had to decide whether the national government could order people to buy health insurance the way "Obamacare" does. In these ways, both of these cases show how federalism divides powers between the state and federal levels without giving either the power to define its own powers.