Coverage of the latest borderline-inscrutable Brexit-related developments from the U.K. is focusing, understandably, on the most immediate, headline-grabbing news. British Prime Minister Boris Johnson stumbles into stunning defeat! Conservatives lose their one-seat majority as Tory MP bolts to the Liberal Democrats! Boris' blunder could bring a snap election between now and the Brexit deadline on October 31!

All of that is true. But it doesn't get to the heart of the matter, which is that the latest machinations, coming on the heels of nearly three years of extraordinary political turbulence in British politics under former Prime Minister Theresa May, points to a much deeper problem, not just in the U.K. but across the West. That problem is the specter of ungovernability.

Self-government requires the formation of a relatively stable majoritarian consensus in public opinion that can be gauged by way of a democratic vote and then translated into action by elected representatives. Those of us who believe strongly in the principle of self-government tend to fret about occasions when something disrupts the second stage in that process: translating public opinion into action. Outright corruption, lobbying by special-interest groups — those and other forms of influence-peddling certainly do cause problems in capitals throughout the democratic world.

But self-government can also break down when a stable majoritarian consensus fails to form in the first place. That's certainly what has happened in the U.K. In the original Brexit vote in June 2016, Leave passed with just under 52 percent of the vote. That was a majority, but not a wide one — and it was staunchly opposed by the other 48 percent of the country. For three years, as a series of opinion polls showed support for Brexit fluctuating right around the 50 percent line, May's government attempted to strike a compromise deal for departing the EU — "soft Brexit" — that could satisfy at least some on both sides and form the basis of a broader consensus. But she utterly failed.

That's not only because the two sides remain diametrically opposed, making compromise impossible. It's also because the disagreement cuts right down the middle of the country's two biggest political parties. Both the Conservatives and the Labour Party are divided into Leave and Remain camps, respectively, which means that neither party can support one side or the other without alienating a significant portion of its voters. That creates a strong incentive in favor of forestalling an electoral reckoning by voting "no" on every actual deal that gets proposed.

It would be one thing if this were a malady afflicting only the U.K. But it isn't.

In regional elections in Germany this past weekend, the far-right party Alternative for Germany (AfD) surged in support, winning 27.5 percent of the vote in Saxony and 23.5 percent in Brandenburg. That sounds ominous. Yet centrist parties won a higher percentage of votes in both elections — the center-right Christian Democratic Union (CDU) prevailed with 32 percent in Saxony while the center-left Social Democratic Party (SPD) won 26.2 percent in Brandenburg. The AfD has a way to go before it wins a plurality, let alone a majority, in a regional or national election.

But as political scientist Yascha Mounk has noted, the AfD's rise has other troubling indirect consequences. Because the centrist parties refuse to form governing coalitions with the AfD, placing growing numbers of seats off limits when forming a government, that crucial part of parliamentary governance is becoming increasingly difficult. In Saxony, for example, the CDU and SPD will likely be forced to form a government with the Greens. That's an extremely broad ideological span, stretching from the center-right through the center-left to a party firmly on the left.

Such governments run the risk of falling victim to ideological incoherence. They may also prove to be extremely fragile. Both flaws can then be used as evidence by the AfD in the next round of voting to demonstrate the fecklessness of the mainstream parties, boosting its own electoral prospects further. In this way, the polarization of the German electorate contributes to making the country more difficult to govern, which makes the polarization, and ungovernability, worse.

Something similar appears to be happening in Italy as well. Following the recent collapse of the governing coalition that united the populist and anti-establishment Five-Star Movement with the far-right League, Five Star has now formed a government with the center-left (and very establishment-oriented) Democratic Party. That incoherence could well ensure further instability, ultimately strengthening the hand of the League's still-quite-popular Matteo Salvini, who now gets to take pot shots from a stance of opposition.

Then there's the situation in the United States, where increasing ideological polarization has combined with the Constitution's myriad counter-majoritarian norms and institutions to create a highly volatile situation in which a figure (Donald Trump) who pursues policies outside the former mainstream managed to become president while winning significantly fewer votes than his rival. In one of several potential nightmare scenarios that could unfold over the next 14 months, Trump's campaign for a second term could culminate with him winning the election while losing the popular vote by an even larger margin than he did the last time — perhaps because of massively lopsided votes in such high population deep-blue states as California and New York.

But arguably even worse could be an outcome in which one of the more left-wing Democrats (Vermont Sen. Bernie Sanders or Massachusetts Sen. Elizabeth Warren) wins the election by a wide margin while the Republicans hold the Senate, ensuring that the new president's popular mandate comes to nothing. That would fuel even more strident left-wing agitation down the road — and even more extreme right-wing opposition to it, with the prospect of actual governance going nowhere at all.

In the latter case, the problem, once again, would be less a failure of our institutions to respond to public opinion than an incapacity of the American electorate's political opinions to cohere into a stable consensus that can be translated into action by elected representatives. With our disagreements becoming deeper and more intractable, we are steadily losing our ability to govern ourselves. That is a problem exceedingly unlikely to end well.