If you think the US midterm results won't massively affect the UK, here's why you're wrong

Whenever we trudge to the polls, it is to cast a vote in what the media and political classes agree is the most significant general election “for a generation”, if not ever.

If it is to choose the vice deputy inspector of Farmyard Milking Equipment in one of Switzerland’s smaller cantons, the outcome will be touted as uniquely significant for farmers, Emmental-makers and the cattle alike.

By and large, as with most hype, such claims are cobblers. The course of history won’t be drastically diverted.

But every now and again, hindsight suggests otherwise. It’s hard to doubt that the world would be exceedingly different today had Al Gore, and not George Dubya Bush, become US president in 2001.

Had a few hundred more ballots been counted in Florida, a Gore administration might have listened to intelligence and foiled the 911 plot. Even if not, he would not have invaded Iraq and initiated the regional chaos that eventually led to the exodus of migrants, which in its turn facilitated Brexit and the wider resurgence of European nationalism.

Gore would also have aggressively addressed the causes of climate change, possibly early enough to limit the temperature rise to a less menacing degree than is now widely expected. For the want of a recount in one state, the counterfactual historian may one day posit from her tent in the Saharan desert that used to be Henley, a whole planet was lost.

We won’t dwell on the last presidential election, and how it and history turned on some 30,000 votes in three rust belt states Hillary Clinton couldn’t be bothered to visit. It’s just too painful.

But two years on, Americans are about to go to the polls again, and the outcome of the 6 November congressional elections feels barely less pivotal.

If “midterms” make them sound like a trifling recalibration of the Washington power balance, sandwiched between the major White House business, they are anything but that. You need not be in the eye of the storm to see the epic implications.

With the Senate virtually guaranteed to remain under Republican control, the serious action concerns the House of Representatives. If the Republicans also hold that, Trump’s vindication will be absolute. Vaunted as the saviour of his party from the punishment that mid-term votes traditionally give incumbent presidents, he will be in a position of mortifying strength. With a pliant Congress in his pocket, he will have a personal mandate to double down on indulging his dictatorial instincts.

And with no political oversight, he will be able to fire attorney general Jeff Sessions and his deputy Rod Rosenstein, and set about nobbling Robert Mueller’s investigation into Russian collusion and the rest.

With the Supreme Court also acting at his behest, he will be emboldened to act on his threats against the freedom of the media which is currently his only effective restraint. He might test the constitutional shackles on a would-be tyrant to snapping point. And he will be free to continue his demolition job on the established world order, snuggling up to despots and alienating allies, until the western democratic powers might be almost as lethally disunited as in the mid-1930s.

If the Democrats retake the House, on the other hand, they will impound his tax returns, use the power of subpoena to examine his business history minutely, and tie him and any legislative programme in chains. The Democrats will protect us against the rogue imperial presidency the framers of the Constitution had in mind.

Today, it appears likely that they have a good shot. Awash with money and voter enthusiasm, psephology savant Nate Silver gives the Democrats a six in seven, or 82 per cent, chance of making the required net gain of 23 seats.

But there is a fortnight to go, and two weeks before the 2016 election Hillary was ahead in the polls. Meanwhile, as Trump travels the country on another race-baiting tour, calling Ted Cruz “beautiful” and thrilling MAGA rallies with fantasies about hordes of sinister Middle Easterners joining the “caravan” of illegals heading towards his sadly still-unwalled southern border, Trump’s post-Kavanaugh approval ratings are higher than at any time since he took office.

This race is beginning to have a nauseatingly familiar feel, though all recent Anglo-American electoral precedent makes predictions a dummy’s game.

You can’t even predict which result would be better for Trump’s prospects of a second term. A Democrat-controlled House would stifle him for the next two years. It would also give him cover for domestic failures and a powerful opposition to run against in the guise of persecuted outsider.

Hindsight might retrofit what seemed to be a Democratic triumph this November as another Democratic disaster.

With foresight, however, you have to worry more about the immediate dangers than any future validation of the law of unintended consequences. For now, it remains unclear whether the rise of nationalism throughout the democratic West is a transient blip or a deeper, longer-term trend. In two weeks we will have a better idea, and the consequences will radiate far beyond the borders of the United States.