Scarred by the 2015 general election and humbled by the Brexit vote, it’s hardly surprising that many in the British political and media class continue to hedge their bets on the 2016 US presidential election, even as the climax of the contest draws near. The instinct for caution is understandable. These have been chastening times in British politics. No one wants to make three wrong calls in a row.

Michelle Obama campaigns with Clinton as Trump hits Ohio – election live Read more

In the case of the US election, however, there is also an uneasy self-awareness of something close to groupthink. Unlike the UK general election or the EU referendum, where divisions within the political and media class were real and deep, there is something close to unanimity about British antipathy to Donald Trump. You have to be intensely anti-American or anti-Clinton – which some are – to positively wish a Trump victory on America and the world.

This helps to explain, though not to excuse, the reluctance to face the overwhelming probability about the US presidential contest. That probability is that Hillary Clinton, with all her strengths and weaknesses, is going to win on 8 November, and is quite possibly going to win by a very large margin. Unless something quite exceptional and so far wholly undetected is happening – the instinct for bet-hedging, you see, is hard to shake off even here – Clinton will be taking over the White House in January.

The clearest and most immediate evidence is in the opinion polls, which consistently show Clinton ahead in the popular vote. That process has been strengthened by the televised debates and, in particular by the final debate, which Clinton clearly won, and in which Trump’s hostility to women seems to have had a lasting mobilisation impact.

That generally strong Clinton lead is also buttressed by local polling in the states where victory is essential under America’s electoral college system. With occasional exceptions, these polls show Clinton on course for a large electoral college win. Dismiss the polls if you like. But the fact that Trump and his running mate Mike Pence are spending time campaigning in states such as North Carolina and Utah shows that they are having to defend their own territories rather than attack in Clinton’s.

All this may change, of course. It’s the safest prediction in the book to say that the contest will narrow in the final days. But the general likelihood is surely that it will not narrow much. By this stage in 2012, only 9% of voters had not made up their minds. It seems unlikely that the proportion would be much different in such a bitterly contested election as this one has been. The big unpredictability this time is voter turnout. If Trump brings lots of new voters to the polls, and at the same time Clinton fails to bring significant parts of the Obama coalition to them, then an upset – which at this stage would be a much tighter Clinton win, not a Trump win – might just happen.

Even in an election as bitter as this one, the claim that lots of states are “up for grabs” is less true than ever. Since 1992, 31 of America’s 50 states have voted consistently in every presidential contest. In most modern US elections, people who consider themselves Democrats vote Democratic, while an equally large proportion of people who consider themselves Republicans vote Republican. A lot is always written at this stage in the campaign about the importance of self-described independents, but these voters tend to lean either Democratic or Republican, and to vote the way they lean too. One estimate puts the proportion of pure independents at only 5%. The veteran poll analyst Charlie Cook says that most voters are already “baked into the cake”.

Part of that is simply because of long-established demographic changes that advantage the Democrats. When Bill Clinton won in 1992, white voters cast 87% of the total vote. By the time of Barack Obama’s re-election in 2012, just 20 years later, the white share had fallen to 72%. One prediction says it will be 70% in November. If each demographic group votes the same way in 2016 as in 2012, the Democratic lead will rise by about 1.5%. Trump has done nothing to combat this and plenty to feed it. In light of Trump’s attacks on women during the campaign, it seems likely that an even higher proportion of white women voters will move into the Democratic column too.

All this appears to be entirely consistent with the much discussed recent book Democracy for Realists by the American political scientists Christopher Achen and Larry Bartels. They argue that elections are not determined by voters’ policy preferences or ideologies, as many of us like to think, but “on the basis of who they are – their social identities”. Certainly the Achen-Bartels thesis chimes with the Brexit vote in Britain. In America, though, where race and ethnicity are such important components of social identities, but not the only ones, Trump’s consistent attempt to appeal to white male voters and alienate minority and female voters does not look like a winning strategy at all; indeed quite the reverse.

The view from Middletown: 'Trump speaks to us in a way other people don’t' Read more

The immediate question, 12 days from the election, is less whether Clinton will win the presidency. It is more whether she can manage to persuade enough voters to elect a Congress that can work with her, not against her, as has been Obama’s fate for the past six years. The Democrats stand a good chance of winning the four seats necessary – Illinois, Wisconsin and two from seven other toss-up states – to regain control of the Senate (where 34 of the 100 seats are up for election). However, control of the House of Representatives (where all 435 members are contested but incumbency is frequently decisive) seems likely to remain in Republican hands. All this suggests that Clinton will not have an easy presidency, even in the first two years, unless Republicans allow that to happen. Since Republicans expect to make gains in the 2018 midterms, they have little incentive to do that.

The Republican pollster Frank Luntz – whom Trump described on Twitter as “a total clown … a low-class slob” – said that if the campaign this autumn were about Trump, then Clinton would win; if it were about Clinton, then Trump could pull it off. Overwhelmingly, the campaign has proved to be about Trump. But that’s now about to change.

Increasingly, Donald Trump looks like a more incidental figure, preoccupied with his hotels and his media ambitions. The big question in American politics is not whether Hillary Clinton will be president. It is what kind of president she is likely to be.