This midterm election season, the Republicans will prevail. Whether they take control of either house of the US Congress or not, it is clear that President Obama and his Democratic partisans, who just two years ago were optimistically touting ‘Change we can believe in’, are now facing changes they’d no doubt prefer were imaginary.

This outcome has been predictable for some time. Since the 1930s, the party in control of the White House has almost always lost seats in the midterms. Yet such facts are unlikely to calm our high-octane political commentators, who have variously held recent shifts in power to herald either a ‘permanent Republican majority’ or ‘40 more years’ of Democratic dominance.