Want to kick-start a political brouhaha? Here’s one way to do it: Pass a law in a red state that affects the citizens of a blue state, or vice versa. Folks in the affected state will be outraged, most people will shake their heads, and a few may even sue.

It happens all the time. Here’s a sampling of state regulations that have made headlines in recent months: Vermont has required food producers that use genetic modification to disclose this fact on the label of any food sold in that state, even if the producer has no facilities in Vermont. Minnesota has prohibited the purchase of electricity that was generated at new coal-fired power plants, even if those power plants are located outside Minnesota. Colorado has legalized marijuana, prompting a lawsuit from neighboring states frustrated with an uptick in drug trafficking within their own borders.

California, not to be outdone, has irked its sister states on a regular basis. One recent California law requires that all eggs sold in that state must come from hens that had enough room to spread their wings in their cages, even if those cages were located outside California. Another regulation requires out-of-state fuel producers to meet in-state carbon-emissions standards if they want to sell their products in the Golden State, which effectively ensures that California—not Congress or the EPA—sets national emissions standards. Yet another law prohibits the sale of foie gras in California if the meat was sourced from birds that were force-fed, a process common in other states. Unsurprisingly, each one of these regulations has prompted a federal lawsuit challenging the state’s ability to control conduct outside its borders.

We have a name for this phenomenon: spillovers. And spillovers are all but universally condemned. It’s not hard to see why. It is unsettling when one state’s policies stretch beyond its territories. It prevents citizens of the affected state from making their own decisions and adopting their own policies. No one wants to live under someone else’s law, after all. If anything, it seems illegitimate for one state’s citizenry to tell another’s what to do. The value of self-rule is so deeply ingrained in our democratic culture that you might think that no good can come from spillovers.

Think harder. Critics of spillovers miss two crucial points about this phenomenon. For one thing, spillovers hardly go against the spirit of our political system—indeed, they are, and always have been, a reality of American government. And, more importantly, they are far from the unmitigated harm to democratic self-rule that critics accuse them of being. While spillovers undoubtedly involve real costs, they also generate substantial democratic benefits. That’s because democracy isn’t just about self-rule; it’s also about ruling together. Because we’ve all retreated to all-too-comfortable red or blue enclaves, it’s very useful for our worlds to collide now and then. Those collisions give us a chance to see how other people live, to live under someone else’s law, to try someone else’s policy on for size. They force us to engage with our opponents and search for common ground. In other words, spillovers ensure that, even in this highly polarized political environment, we still engage in the everyday practice of pluralism.

Spillover Nation

If you’re worried about spillovers, well, there’s a lot to worry about. That’s because they are absolutely routine in a highly integrated, tightly networked system like ours. When California passes climate-change regulations, Detroit automakers are forced to manufacture more environmentally friendly cars for everyone lest they lose the huge California market. When Texas insists that the textbooks in its schools question evolution, school boards across the country find themselves purchasing textbooks that are considerably more conservative than their population. When Wisconsin refuses to do business with any company that has violated federal labor law, companies must change their practices nationwide in order to compete in the state. When Virginia and Georgia maintain lax gun rules, firearms flood into New York via the “Iron Pipeline.”

Policy-making would certainly be simpler if states’ policies never crossed territorial lines. Every state could regulate entirely as it sees fit. But these United States are closely knit. When states regulate shoulder-to-shoulder in a tight policy-making space, it’s inevitable that they will end up jostling one another. Regulatory overlap is a stubborn fact.

But even if you could wish away the current state of affairs, why would you? We could surely try to turn back the clock and return to a simpler time. But the price of maintaining clear jurisdictional lines and limited policy-making domains is too steep. We’d have to give up on a nationally integrated market. We’d have to give up on a nationally integrated political system. We might even have to stop our citizens from crossing state lines. In the abstract, self-rule sounds like an unalloyed good. In practice, it isn’t. Self-rule always requires a trade-off. And when we recognize the many goods we’d have to sacrifice to attain it—the goods associated with integration—the trade-off is less appealing.

Indeed, there are good reasons not just to tolerate spillovers, but to value them. There are genuine benefits associated with living under someone else’s law. Democratic self-rule is always played as if it were a trump card in these debates. It’s not. There are serious democratic goods associated with the chaos and consternation that spillovers generate. Spillovers cause friction, and friction has its uses in a political system.

That may be a counterintuitive point. But democracy benefits top to bottom from spillovers. That’s because interstate spats spur democratic engagement, and democratic engagement is in short supply in this day and age.

How Spillovers Fill the National Policy-Making Vacuum

Let’s start at the top: the national policy-making process. Needless to say, that process is not working. In this highly partisan environment, members of Congress think it’s safer to name post offices than to pass laws. They leave the hard democratic decisions to the states and localities, where policy-making is easier because we’ve sorted ourselves so neatly into red and blue enclaves. What Bill Bishop calls “the big sort” has ensured that most of us are nestled comfortably in the domain of our choice, whether it resembles Fort Worth or Portland.

It’s all too easy for national elites to relegate tough questions to local decision-makers rather than forge a compromise at the national level. Federalism gives license to national politicians to take the easy way out. Just as it was once too easy to let states in the Jim Crow South resolve questions of racial equality for themselves, today it’s too easy for the national government to let states navigate the hard questions raised by gun rights, gay rights, and abortion.

Red and blue silos are not the products of a well-functioning national democracy. Democracy means hashing things out. It’s perfectly fine if, at the end of the day, we decide that states and localities can pursue different paths. A well-functioning democracy doesn’t require rigid uniformity; it requires us to deliberate about which departures from national policy are consistent with our norms and which are outside the bounds. Nowadays, however, we aren’t deliberating—we’re just punting. The reason states and localities are pursuing such different paths isn’t that we’ve decided that, all things considered, these are worthy paths to pursue. It’s because we are so divided that we can’t even have a conversation about national norms in the first place, let alone make a collective decision about when and how they should matter.

Spillovers are one solution to this problem. For one thing, they thrust certain issues onto the national agenda, which is incredibly hard to do these days. When one side forces its unwelcome policies on the other, the aggrieved party almost inevitably looks for a federal referee. When California enacted strict environmentalist policies, auto executives from Detroit begged the EPA to step in and preempt them. When Hawaii threatened to legalize same-sex marriage, opponents of marriage equality sought assurances from Congress that they need not recognize same-sex marriages performed in other states. Spillovers, in short, pull national elites into the conversation. And once national elites are drawn into the conversation, they will begin pounding the table and pressing for change, thus drawing even more attention to an issue.

California’s egg law shows how spillovers can tee up an issue for national resolution. Insisting that so-called “battery cages” are inhumane, California adopted a law in 2010 that banned the sale of eggs laid by hens that had been confined in cramped spaces. Because the regulation affected so many out-of-state companies, it kicked off a nationwide debate. California insisted that its law was necessary to protect animal welfare. Missouri argued that the law placed egg producers between a rock and a hard place: Either invest millions in new cages or else forfeit the vast California market entirely.

This spillover caused by a state law generated a valuable national debate that otherwise might never have occurred. By 2012, Congress was considering a federal “egg bill” that would have made California’s standards binding on the whole nation. Interest groups began commissioning reports on the costs and benefits of battery cages. Conditions at factory farms—a topic that most Midwestern politicians prefer to ignore—became a major news story. Political pressures generated by the debate forced big agribusiness to compromise with animal-rights groups and support some restrictions on battery cages. Although that compromise was not enough to secure final passage of the federal farm bill, a similar deal may be sealed when the next farm bill comes up for debate later this year. In the meantime, the California law went into effect in January 2015, and the debate California set in motion rages on. Whatever its merits, California’s egg law raised public awareness and drove the parties to the negotiating table.

Spillovers don’t just get issues on the national agenda; they also help break through Washington gridlock. Minorities in Congress often use procedural tools to block reforms that they oppose. When the states are doing nothing on an issue, filibustering is a no-brainer—it prevents the enactment of a nationwide policy and thus ensures a total victory to the minority. But when spillovers do exist, the calculus in Washington becomes more complicated. Even if opponents of change successfully filibuster a bill in Congress, an unchecked spillover may have regional or even national effects. The states, in effect, allow for backdoor national policy-making. As a result, the interests blocking change at the national level suddenly have an incentive to come to the bargaining table. Pure obstructionism in Congress doesn’t reap the same rewards, and a compromise solution becomes more likely.

Spillovers also limit the power of special interests. Although interest groups are often able to block legislation in Congress, they have a harder time blocking legislation in all 50 states. Environmentalists, stymied in Congress by big business, convinced California to adopt carbon-emissions standards. Opponents of drones, thwarted in Congress by Boeing and Amazon, have convinced nine states to ban drone flights over private property. To be sure, the special interests that control Congress can pass legislation at the state level, too. But these state outlets matter much more to groups that don’t have Congress in their pocket and thus help level the playing field. By creating a spillover, a single innovative state can put an item on the national agenda even if nearly everyone else—Congress, interest groups, and other states—would prefer that the issue go away. State spillovers at least push self-interested politicians to take a position on a question they’d rather duck, which is a democratic good unto itself.

Spillovers further ensure that policy debates are practical rather than speculative. It’s always helpful to pass a reform at the state level because it proves a policy can work in practice. By forcing automakers to limit emissions in the 1970s, for example, California proved to the world that cars could be both efficient and affordable. That’s precisely why Justice Louis Brandeis likened the states to policy-making laboratories for the rest of the country. Spillovers add a new twist to this analogy. Since spillovers often have regional effects, they create much bigger laboratories. Experiments yield more data in less time. Successful experiments quickly become models for national reform. Unsuccessful experiments get shut down, becoming a cautionary tale in future policy debates.

Think about the ongoing debate over the “right to be forgotten.” In the past several years, reformers have argued that Internet users should be able to delete publicly posted data in order to prevent it from being discovered on search engines. Over the strong objection of Google, the Court of Justice of the European Union recently recognized this “right to be forgotten.” Tech companies, appealing to notions of practicality, expense, and freedom, have so far prevented Congress from recognizing such a right. But California recently passed an “online eraser” law that requires websites directed toward minors to allow those minors to remove publicly posted content. Because California minors access websites from companies outside the state, this law has created a sizeable spillover.

That spillover, in turn, has generated a major national debate. Companies outside California have argued that they should not be forced to delete minors’ data. Google, which spent $17 million on lobbying last year, has insisted that the “right to be forgotten” is expensive and impractical. Despite the powerful interests blocking debate on the Hill, California’s spillover got the issue onto the national agenda. Moreover, companies like Google can no longer prevail merely by shutting down debate in Congress. And when the congressional debate does take place, we’ll have had a chance to test Google’s arguments against reform in a “laboratory” that is a good deal bigger than California. If the experiment proves workable, California’s “eraser” law may serve as a model for future regulation; if the experiment fails, policy-makers will be all the wiser.

How Spillovers Improve State Policy-Making

Spillovers likewise promote a healthy democracy at the state level. The “big sort” doesn’t just excuse national officials from doing the tough work of democratic compromise. It excuses state officials as well. No state or city is homogenous, which means that state and local officials always know that some of their constituents are unhappy with the enclave they’ve built for their citizens, be it red or blue. But arguments for change are usually presented by people who lack the votes to do anything about it, making it easy for state and local politicians to brush them aside. There’s little reason to cross party lines or compromise with those who seek change, something that can result in the same type of gridlock that exists at the federal level.

Spillovers force state and local politicians to suit up and get in the game, just as they do with national politicians. Local officials are often able to ignore their own dissenters. But one jurisdiction’s dissenters are another’s majority, which means they can impose from the outside positions that the minority cannot demand from the inside. And it’s hard to ignore the opposition when it is imposing its views on your unhappy constituents. Oftentimes, as noted above, state politicians will look to a national referee when they encounter a spillover problem. But when a national umpire is unavailable, spillovers force state and local officials to do what they are supposed to do: politic, find common ground, and negotiate a compromise that no one likes but everyone can live with.

A classic example is the Uniform Commercial Code (UCC), an act designed to harmonize commercial law across the 50 states. By the middle of the twentieth century, differing state regulations were causing huge headaches for interstate companies, which were subjected to conflicting obligations. A shipping company with operations in New York, headquarters in Delaware, warehouses in Pennsylvania, and clients in California might find itself subject to four sets of contradictory laws. Different interest groups in different places were blocking the states from offering a sensible fix. Spillover problems grew so serious that the National Conference of Commissioners on Uniform State Laws drafted a model uniform code in consultation with academics and state officials. Scholars often assume that the UCC succeeded because it was a “model” code. In fact, the UCC was far from anyone’s ideal. It was substantially revised to satisfy different state interests, and parts were deliberately left vague to avoid irritating powerful interest groups. Academics wring their hands over this type of politicking, but it’s precisely this type of compromise that made it possible for every state to adopt the UCC. The UCC was just the type of second-best solution that spillovers generate. And second-best solutions tend to be the ones that get passed.

The lesson even holds true lower down the governance hierarchy. It turns out that intrastate spillovers can be just as beneficial as interstate ones. Localities often pass measures that ruffle the feathers of neighboring localities, just as states pass measures that ruffle the feathers of neighboring states. When this happens, aggrieved cities often ask the state government to step in as referee. Ultimately, this intrastate conflict ends up fostering the same brands of accommodation and compromise that we see among state and federal officials.

One telling example comes from Arizona, where cops in Tucson and Phoenix recently sponsored a number of gun buyback events. Furious gun-rights advocates worried that many Arizonans would trade their firearms for cash, and that the firearms would be destroyed. The buyback programs set off a statewide debate. Activists on both sides looked for a compromise. Ultimately, the governor signed a bill that allowed gun buybacks but required that law-enforcement officials sell the purchased guns to a firearms dealer instead of destroying them.

Sometimes localities pass regulations that spill over not just city lines, but state lines as well. For example, Alameda County in California has adopted an ordinance requiring any manufacturer that sells its prescription drugs in that county to develop and fund a “disposal plan” for those drugs. A federal court recently upheld that law over the strong objection of out-of-state drug companies.

Spillovers and the Habits of Citizenship

Spillovers matter even at democracy’s most granular level: the habits of everyday citizens. Political enclaves are an easy solution for political elites, but they’re also too easy for the rest of us. When we sort ourselves into comfortable right- or left-thinking communities, it’s all but inevitable that we’ll ignore those with different views. Enclaves encase us in a protective policy-making bubble, shielded from laws with which we disagree. Opportunities for democratic engagement are reduced. More importantly, incentives for democratic engagement are weakened.

Spillovers enlist everyday citizens in the practice of pluralism. At the very least, they prevent us from being oblivious. Indeed, spillovers ensure that those least likely to be receptive to an idea—those nestled in enclaves with the opposite policy—confront that idea directly. The progressives who decry social conservatism might actually have to read the Texas school board’s preferred texts and reflect on why other Americans think these issues are important. Opponents of same-sex marriage might find themselves living next door to a same-sex couple who got married in another state. People who insist that environmental regulations cost consumers too much might find themselves driving inexpensive cars that meet California’s low-emissions standards.

Spillovers also help us identify where compromise can be found. In politics, we usually ask voters what they want rather than what they can live with. But the second is a far more important question. Spillovers elicit the answer to that question by forcing us to live under someone else’s law. We must drive a more fuel-efficient car. Or teach from a textbook more conservative than we’d prefer. Or live next to someone who owns guns that would be difficult to purchase in-state.

These real-world experiences matter. It’s always easy to oppose something in the abstract, but reality tends to be more complicated. In many instances, spillovers will convince us that the policy isn’t as bad as we thought.

Sometimes engaging directly with a policy will cement our view that it’s a mistake, and that matters as well. In our highly polarized system, it sometimes seems like we disagree about everything. Spillovers help us sort out annoying differences that prompt little more than a collective shrug from genuinely deep disagreements that require our collective attention. They help us distinguish the policies we’d reject in a poll and those we’d actually work to overturn. Spillovers can thus tell us a great deal more than polling or voting about whether a modus vivendi can be had. In other words, in an era defined by polarization, spillovers can be a powerful mechanism to mitigate the “big sort”-ing of America.

Our Forgotten Federalist Lesson

What’s so striking about the near-universal hostility to interstate spillovers is that it stands in stark contrast to one of federalism’s central tenets. While we mourn friction among the states, friction between the states and the federal government has been a celebrated feature of American democracy since the early days of our republic. When federal policy spills over into a traditional state domain, or state policy spills over into the federal realm, it causes the same kind of friction that arises from interstate spillovers. This friction has led to all sorts of problems, including inefficiency, conflict, and division. Federalism scholars don’t deny these harms. They simply insist that we also pay attention to the productive possibilities associated with state/federal friction.

It’s time to apply this lesson to the horizontal realm. Like friction between the states and federal government, friction among the states comes with both costs and benefits, and it’s here to stay. Our goal, then, shouldn’t be to eliminate interstate friction, but to harness it—taking advantage of its many democratic benefits while avoiding its more serious costs.

The fact that even localities can generate spillovers confirms an important lesson. In this day and age, we are so tightly bound to one another that, in effect, everyone regulates each other. When one jurisdiction moves, it inevitably tugs others along with it. We’d be better off figuring out how to benefit from the friction generated by regulatory overlap rather than hoping it will just go away.

The costs of spillovers are real and important. Sometimes the spillover game won’t be worth the candle. If states impose too many conflicting regulations on companies, the economy suffers. If states can slough off the costs of their policies on other states (states with lax pollution regulations impose costs on states downriver or downwind), people suffer. And sometimes we will be so divided on an issue that compromise isn’t possible and spillovers can only harden our positions.

Our point isn’t that spillovers are an unmitigated good. It’s that the benefits of interstate conflict—interaction, accommodation, and compromise—are substantial and have been overlooked in this debate. When we are forced to live under someone else’s law, we learn to accommodate one another’s preferences, to identify everyone’s second-best solution, to engage in the practice of pluralism, or to at least to figure out what we really think about a question. It’s not easy, and it’s certainly not fun. But these democratic benefits should matter when we tote up the costs and benefits of spillovers.

The reason that the debate has been so one-sided thus far is that the arguments against spillovers—rooted as they are in the principle of self-rule—are so intuitive. But it’s worth remembering that while our democratic commitments may begin with self-rule, they should not end with it. Every community would like to live by its own lights. Every person would like to live by his or her own lights. But we quickly learn that our preferences differ. Democracy requires us to do just what spillovers require us to do: Work it out. Sometimes we work it out directly. Sometimes we need a referee. Sometimes we just take our lumps and live under a policy we don’t like. And we do so for a simple reason: We’d rather live with other people than without them.