Trump’s victory was predictable, and was predicted, but not by looking at polls. Polling has taken a beating recently having failed to predict the victory of David Cameron’s Conservative Party in the British general elections, then Brexit, and now the election of Donald Trump. One can argue about what’s wrong with the methods involved, but more fundamentally what polls do is to treat these phenomena as isolated events when they are in fact the product of a common set of causes 30 years in the making.
There are two issues at play here. The first is known as Galton’s problem, after Sir Francis Galton, the inventor of much of modern statistics. Galton’s problem is that when we treat cases as independent—the British election, Brexit, the U.S. election—they may not actually be independent. There may be links between the cases—think of Brexit’s Nigel Farage showing up at Trump's rallies—and there could be subtler contagion or mimicry effects in play as information from one case “infects” the other, changing the dynamics of the system as a whole. Could there then be a higher set of drivers in the global economy pushing the world in a direction where Trump is really just one part of a more global pattern of events?
Consider that there are many Trumpets blowing around the developed world, on both the right and the left. On the one side, insurgent right-wing parties are bulldozing the vote shares of traditional centrist parties all over Europe. For example, the Finns Party is the second-largest party in the Finnish parliament. In Sweden, the Swedish Democrats are the third-largest party in parliament. In Hungary, Prime Minister Viktor Orban’s political party, Fidesz, runs the country having won two elections. Meanwhile in France, the most popular political party is the National Front, which in all scenarios but one—whatever such exercises are actually worth—is expected to win the first round of voting in the 2017