The question remains, of course: why didn't Romney, who has known for at least five years that he was going to run for president, make his tax returns so watertight that they could be publicly released? (His father released ten years of tax returns when he was governor of Michigan in the 1960s.)  Even if it cost Romney a few million dollars by foreswearing tax havens not available to ordinary Americans, why didn't he instruct his accountants to draw up a set of returns that would look fine even if the Democratic National Committee posted them on the internet? He was trying to become the most powerful man on the planet; might that not have been worth the trouble, if only for a few years? The answer is a mystery even to Romney's closest advisers; perhaps it's just that the rich are different from the rest of us. Yet it's clear that he pays every penny required under federal law, and for Reid to accuse him of paying nothing is disgraceful.

"There are two things that are important in politics," said Mark Hanna, who managed William McKinley's presidential campaign against William Jennings Bryan in 1896. "The first is money, and I can't remember what the second one is." Americans have lost 38 per cent of their net worth in the period since 2007. For most of them — those on median incomes — this means that 20 years' accumulation of wealth has been wiped out in five years, four of them under Obama. The median wealth for a US family was $126,000 in 2007 and is $77,000 today. The collapse in house prices, stock prices and incomes (down from $50,000 a year to $46,000 for median incomes) means that the middle classes have witnessed a real-life, real-time catastrophe in the past half-decade. If Obama wins, it will explode the theory that "it's all about the economy, stupid."

If Obama loses, it will also explode the theory that Americans are fearful of voting against a black president for fear of seeming racist, even though the same people had voted for him in 2008 partly because they did want to see a black president in the White House. Then there's what's known in political circles here as "the Bradley Effect". Tom Bradley was the first black mayor of Los Angeles, who in 1982 ran for governor of California. He seemed to be headed for victory on the basis of the polls, but he lost. It was later discovered that even in telephone polling, voters lied about their voting intentions to avoid sounding racist.

It is customary in every election — British as well as American — for the candidates to intone that the stakes could not be higher, that this is the most important choice for a generation, and so on. It's in the media's interests to agree, not least in order to snaffle that $6.5 billion in election advertising  looking for outlets. Yet Karl Rove's Political Action Committee, "American Crossroads", might not be named hyperbolically. In 1979 the number of Americans on means-tested benefits was 7 per cent; today it is more than 30 per cent. The number of Americans who get their food from the government via the food stamp programme has exploded from 17 million only 12 years ago to 46 million today. Since 2009, when 2.6 million signed on with new employers, half a million more than that signed on for disability allowances. Under Obama those trajectories will undoubtedly continue, and probably worsen. 

The dependency culture is the Democrats' best electoral friend. Romney appreciates that it leads to Great Power suicide. The road to serfdom beckons — but America does not have to go down it.