The grand view of American politics is that Republicans have a lock on Congress, while Democrats have an inbuilt White House advantage. Last month’s Republican victory shored up that theory. Conservatives reliably turned out for the midterms, while liberals hibernated.

Come the glamour of 2016, Hispanic, millennial, single female and African American voters will be back in force. All that Hillary Clinton need do – or whoever takes the Democratic nomination – is tick the right boxes and let demography fix the rest.

Such is the US left’s world view. It is also a measure of its intellectual poverty. Whatever liberals are smoking, it is no stimulant to new ideas. The left’s sense of destiny is based on America’s shift to a minority-majority nation within the next 30 years. As the white vote shrinks, each presidential race will be harder for Republicans to win. What is missing is a compelling reason for people to embrace Democrats, as opposed to rejecting Republicans. For the time being, the latter can be relied upon to offend minorities – notably Hispanics. But Democrats have remarkably little new to say about the future of America’s middle classes, regardless of ethnicity.