America is terribly polarized.

And it’s all on account of California.

The trouble is not merely that California itself is such a politically polarized place. Or that California contributes to the many causes of polarization: partisan media, ideological movements, cultural atomization, big-money politics, technological change, economic anxiety, and income inequality.

No, the artichoke heart of the matter is that California is simply too big, too exceptional, and too 21st-century to fit an America governed by 18th-century rules and mid-20th-century nostalgia.

The way in which California fuels the polarization of national politics is paradoxical: We divide America not because we are divisive, but because we balance out the country culturally and politically. California, with the help of New York and a few other big states, is a large progressive check on a conservative country, making America a 50-50 nation in matters political.

But America’s political system is simply not set up to work in such a narrowly divided polity. The United States is famously a system of checks and balances, in which governance requires broad consensus. One path to consensus is a strong ethic of compromise and bipartisanship—an ethic that is currently elusive. The other, more reliable way to achieve consensus is to have one political party that is so dominant in government that it can make changes easily; the minority party, rather than obstructing, knows that it can’t win and thus has more incentive to cooperate and contribute ideas.

California defeats both paths to national consensus. Our own polarized political culture (with California Democrats veering ever further left, as California’s remaining Republicans keep turning right) doesn’t inspire the bipartisan spirit. And California’s Democratic dominance effectively cancels out the GOP stronghold of the American South, preventing Republicans from achieving stable governing majorities.

The resulting close split drives partisan conflict, polarization, and gridlock in national politics.

As University of Maryland political scientist Frances Lee shows in her book Insecure Majorities: Congress and the Perpetual Campaign, the country produced more compromise and progress from 1933 to 1981, when Democrats dominated Congress and presidential elections usually produced landslide victors. But in the late ’80s and early ’90s, as California transformed into a Democratic stronghold, the dynamic shifted. There hasn’t been a presidential landslide (in which the winner got more than 70 percent of the electoral votes) since 1988. And the House and Senate have had relatively tiny majorities, with party control of each chamber flipping multiple times.

Because elections are so close, American politics has become so relentlessly competitive as to be dysfunctional. To win in this system, parties magnify their differences at the expense of governing, and exploit every tiny advantage, from election procedures to the redistricting process. Lee cites a Californian, the House Majority Leader Kevin McCarthy of Bakersfield, as an especially innovative practitioner of strategies to resist any cooperation with the other party.

“Intense party competition for institutional control focuses members of Congress on the quest for partisan political advantage,” she writes, in describing recent decades of government shutdowns and partisan investigations. “When party control seemingly hangs in the balance, members and leaders of both parties invest more effort in enterprises to promote their own party’s image and undercut that of the opposition. These efforts at party image making often stand in the way of cross-party cooperation on legislation.”

When party control seemingly hangs in the balance, members and leaders of both parties invest more effort in enterprises to promote their own party’s image and undercut that of the opposition … often standing in the way of cross-party cooperation …

This dynamic explains maddening and polarizing behavior by both parties. It also creates two deep grievances involving the Golden State.

The first is the complaint, heard increasingly in other parts of the United States, that California is a great nullifier. Many Americans simply can’t accept the power of California’s huge population, wealth, and overwhelming cultural and technological awesomeness to frustrate efforts to enshrine their old-fashioned bigotries in national policy. It makes America even madder that we’re not at all sorry about our exceptionalism, but so what? To quote the famously pithy Austro-Californian philosopher and statesman Arnold Schwarzenegger, “Everybody pities the weak. Jealousy you have to earn.”

The second grievance is California’s own. The rickety, old U.S. Constitution routinely hamstrings our democratic preferences. The 2016 election made this plain: We voted in record numbers for Hillary Clinton, who won the national popular vote by nearly 3 million votes, but saw our choice nullified by the electoral college, which makes the votes of people in a lightly populated state like Wyoming three times more valuable than our own ballots.

Meanwhile, the House of Representatives gives outsize power to rural voters across the country, whose values are very different from those of urban, cosmopolitan California. Then there’s the U.S. Senate, which, in allocating California the same two senators as the 49 lesser states, is committing an ongoing crime against truth, justice, and Golden State democracy. An important note: The Senate’s structural underrepresentation of California is a rare provision specifically exempted from constitutional amendment in the U.S. Constitution; no matter what, every state is guaranteed the same number of representatives in the upper house of our national legislature. (The U.S. Senate, unlike Pelican Bay, never releases its prisoners.)

My fellow Californians, the next time some American apologist tries to defend the country’s constitutional structure as anything but a conspiracy against California, look them in the eye and say: “North and South Dakota, dude?”

Since California is the heart of the problem, there are two ways to address American polarization. The first and better way is through democratic reform. Let’s elect the president by the popular vote. Let’s nix the Senate and replace Congress with a 21st-century parliament, in which one state’s huge size doesn’t count against it.

In such a system, one party, the Democrats, would control Congress and win most presidential elections, dominating governance and encouraging Republicans to cooperate and create real policy alternatives instead of obstructing.

But if the Constitution remains inviolate, then the United States would be far more governable if California were allowed to leave and form its own country. America would be far poorer—in economy and culture and spirit—but Republicans would hold enough sway to pursue their designs, and be held accountable for the results.

For now, however, the country is in a stalemate. The rest of America has little incentive to surrender a constitutional order that gives it more representation than it deserves. And California has no incentive to surrender to an anti-democratic America that nullifies our values and democratic choices.

If the United States is ever going to cure its polarization, something will have to give: The American Republic. Or California.