And a third, related, explanation is that elites cannot easily manage America’s raucous democracy. Populist insurgencies are written into the source code of a polity that began as a revolt against a distant, highhanded elite. The electoral college devolves power from the centre. Primaries attract the 20% of eligible voters most fired up by politics. Candidates with
money behind them—his own in the case of Mr Trump, someone else’s for Mr Cruz—can sneer at their party’s high command.
Hence populists and antiestablishment candidates make frequent appearances in American presidential races. But as the thrilling spectacle runs its course and voters reluctantly compromise with reality, they tend to fade. That usually happens early (Pat Buchanan, a Republican firebrand who promised a “pitchfork rebellion” in 1996, won the New Hampshire primary, but was out of the race by the end of March). On the rare occasion when insurgents win the nomination, they have collapsed at the general election: Barry Goldwater lost 44 of 50 states in 1964. Those who stand as independents (as Ross Perot did in 1992) have also failed—which would not bode well for a selffinancing candidate like Michael Bloomberg.
For the Democrats, history is likely to be repeated in 2016. Even if he wins Iowa and New Hampshire, it is hard to see Mr Sanders thriving as the race moves to the delegateheavy South. Mrs Clinton has money, experience and support from black Democrats. National polls put her 15 points ahead.