“Lower the temperature,” Joe Biden tells us. Facing a country troubled by civil unrest while contending with a pandemic for nearly a year, it’s understandable the incoming president seeks unity.

But the goal of “lowering the temperature” illustrates a broader point: politics has gotten too hot because the stakes have become so high. The assault on the Capitol, encouraged by President Trump, inflamed public passions to a previously unimaginable degree. However, one should not be duped into thinking that Trump is the origin of divided politics.

Over the last 20 years the thinking of Democratic and Republican voters has diverged further and further. The gap is worryingly large. According to a recent study, some 15 percent of Republicans and 20 percent of Democrats stated that the United States would be better off if members of the opposing political party “just died.” Some 18 percent of Democrats and 13 percent of Republicans approved of the use of violence in politics.

How did we get to this point? Any account that minimizes the role of Trump or his high-profile supporters, such as Sens. Josh Hawley and Ted Cruz, is dishonest. Character matters, as Americans have learned the hard way. But we must also recognize the troubling trends that have existed for a long time. Jan. 6, 2021 was not a self-contained problem.

The simple explanation for this problem is that national public affairs have become all-encompassing. American politics is now a winner-take-all tournament Washington, D.C.

This is not how it’s supposed to be and it wasn’t always this way.

As most of us remember from high school civics, the American federal system relies on checks and balances. These include two complementary levels of government: national and state. The states do not derive their authority from the national government. They exist independently.

Constitutionally, federalism is a feature, not a bug. State and national governments must coexist and work together, each within its proper sphere, to address citizens’ concerns. State governments are intended to check the power of the national government.

The problem is that state governments have become too reliant on the national government, depending on the feds to provide support for everything in varying degrees from education to health care to drug policy. Instead of 50 different organs of policymaking and 50 different governments providing a counterbalance to the federal government, we increasingly ask Washington to handle all our problems.

Excessive centralization means the stakes of losing in Washington have become unbearably high. While the blow from losing a policy contest at the state level can be softened in many ways, losing Washington could be disastrous. Defeat at the national level means not only forfeiting control over federal policy, but over state policies as well. That increases the acrimony.

So the only hope for peaceful self-government is to halt the centralization and return to more independent governance at the state level. This would not only lessen the stakes at the federal level but also offer citizens more control over their government.

Why is this so? It is much easier for citizens to help craft new state-level policies or eliminate ineffective ones than it is at the vaster, less-personal national level. If worse comes to worst, people can always vote with their feet and move. Indeed, that is what many citizens are doing as they flee incompetently governed states like California for competently governed states like Texas. But if the national government goes downhill, what can we do? An individual’s one vote in a national election is inconsequential and expatriating is difficult.

Decentralization has its own problems, of course. There are situations where a top-down response from Washington may be appropriate. But these are the exceptions, not the rule. It’s clear our political acrimony stems from too little decentralization, not too much. To lower the temperature of politics, we should raise our commitment to federalism while limiting the scale and scope of politics as a whole.

Healing the political divide in the United States is no simple task. We’ve spent decades placing more decision-making authority in the hands of the federal government and then pulling away from one another as a consequence. States must take some authority back. Citizens must take the lead in demanding this. We, the people, bear ultimate responsibility for good governance.