'Federalism' was a word of the week. Here's how it really works.

In the last week, President Donald Trump told reporters,"When somebody is the president of the United States, the authority is total." That claim, as many pointed out, contradicts the U.S. Constitution. While he later modified his claim, this was only the latest foray in the pandemic-prompted national discussion about federalism.

This conversation has touched on three myths about how the U.S.'s federal system operates. Let's examine each one in turn.

1) Federalism is not a code word for states' rights and ability to get things done.

Last week, many observers were applauding governors and chastising the federal government for inaction. In response, Nikki Haley, a Republican and the former governor of South Carolina, suggested that citizens should pay less attention to the federal government and "look no further than the governors" to "save people's lives" and "keep the economy afloat."

But Haley is wrong when she suggests that governors can handle the pandemic and that "[o]ur Constitution has it right: Keep control and decision-making close to the people." In doing so, she promotes the outdated concept of dual federalism, which equated federalism with states' rights and states' ability to make effective policy on their own. The founders designed a system with a strong central government capable of coordinating state action. They did not intend states to meet national emergencies on their own. As John Jay wrote,"a good national government," with its capacity to unite and coordinate the states, is "necessary" to deter foreign invasion.

2) Nor does it just mean that states are insignificant.

Trump was touting a highly centralized conception of federalism to justify his claim that he had the authority to order states to reopen the economy, saying that the governors "can't do anything without the approval of the president of the United States."

3) The constitution is vague about where states' authority begins and the federal government's ends.

The president's statements sent people scrambling to dust off their Constitutions. But the Constitution only loosely defines the divisions of authority. While the Tenth Amendment says that any powers not assigned to the federal government or "prohibited" to the states "are reserved to the States respectively, or to the people," that is not an "insurance policy," as one law professor put it. In practice, the federal and state governments share a great deal of policymaking. This relationship has evolved — and continues to evolve.

We have federalism because states find it hard to coordinate.

State governments aren't built to handle national crises. They have difficulty coordinating their efforts because of what social scientists call collective action problems. If each state takes the actions that best protect it and its citizens, those actions may harm citizens in other states — as when they compete for ventilators. Governors naturally put their own residents' welfare first, even if they know that every state would be better off if all coordinated. No one was ever reelected governor of Rhode Island for helping the people of New York.

Interstate rivalry led the U.S. founders to replace the loose Articles of Confederation with a plan for a national government that had more "vigor," as Alexander Hamilton emphasized — one that could make decisions and act on issues affecting the entire nation.

States are working to forestall future competitive breakdowns, forming regional pacts to coordinate how and when to reopen their economies.

The federal government is getting a pass because institutions designed to restrain it are failing.

Instead of coordinating a national pandemic response, the federal government has compounded the collective action problem, as shown by Jared Kushner's striking assertion that the national stockpile is "ours" and not a resource for the states. The founders pointedly included safeguards to prevent national government overreach or shirking; those include the judiciary, separation of powers, state representation in federal decisions, intergovernmental councils, the people themselves and states' ability to push back. Another safeguard emerged later: the party system.

In a robust federal system, these reinforce one another, a kind of fail-safe system intentionally full of redundancies. The founders worked to design an institutional immune system so that no single person or faction could disrupt the government. They hoped that federalism might sustain democracy.

What might threaten this robustness would be what the Federalist Papers called a "lack of diverse interests": If the judiciary, the branches of federal government, and the internal workings of political parties were all aligned in their thinking or had a culture of obedience, and if the public were apathetic or ill-informed, then the safeguards may simultaneously fail.