I’m writing this as the US election is in progress and before votes have begun to be counted. My guess (and hope) is that Clinton will win. But even if she does, I don’t think things will get better. For one thing, the insurgent forces that created the Trump onslaught will not go quietly into that good night. The explosion of populism that 2016 has brought is not just a passing rage. Something has changed. Something big. Things that we have taken for granted for decades are suddenly looking fragile. Political theorists tell us that liberal democracy is a surprisingly resilient organism. My feeling is that it is fragile, and the events of 2016 have provided us with some insights into ways that it might begin to fail.

All of which is by way of introduction to a remarkable essay that the Economist has published this evening. It’s about precisely this subject: the fragility of liberal democracy, and the circumstances under which it might flip. It’s really worth reading in full, but here’s the central passage.

What is a political institution really? It is a social consensus supporting particular behaviour in particular contexts, designed to prevent people from pursuing narrowly rational actions when those actions are detrimental to long-run welfare. We all agree we are going to do things a particular way, because when there are defections from doing things that way, society doesn’t work as well. We all agree that we are going to pay at the end of the meal, even though we have already eaten, because when too many people defect from that norm the experience of dining out becomes dramatically worse for everyone. We all agree that politicians shouldn’t base their campaigns on falsehoods, because the norm that campaigns should be at least somewhat rooted in reality makes for better public policy.

Inevitably, people have an incentive to defect from the norm established by an institution. Not paying for dinner is easier, if you can get away with it. Lying throughout a campaign is a useful strategy, if you can get away with it. For useful institutions to persist, then, there must be punishments for defection from the norm. Sometimes there are civil or criminal penalties for defection, though in the absence of a true social consensus regarding the norm those penalties might be too weak to support the institution (think about extralegal use of alcohol or drugs). Most of the time, social opprobrium is a critically important part of the process of defending the norm. Society relies on its members to shame people who run out on dinner bills. It relies on its members, and on institutions like political parties and the press, to shame and discourage people who flout important political norms. In liberal democracies, when an important political figure gets caught in a blatant lie, or ignores a public norm that leaders should not engage in open racism, or declares his intention to violate constitutional principles, we expect the public outcry to be fast and furious, and we expect the figure to suffer some professional consequence as a result: to face a loss of power, or a loss of status, or a loss of position.

If these social costs decline, or if public shaming becomes less effective, society can flip from a good institutional equilibrium to a bad one. If the cost to defecting becomes easier to bear, then more leaders will do it, which further reduces the stigma of defecting…

It seems to me that what Trump in the US and the fanatical Brexiteers in the UK have been doing fits this template pretty accurately. Their method has to undermine and erode the social consensus surrounding politicians’ behaviour which used to keep things on a moderately level playing field. And in so doing they’ve triggered a downward spiral in which we are all enmeshed — and which they will not be able to control, even if they wanted to. The maelstrom starts here.