The American presidential election is over. Republican candidate Donald Trump has virtually no hope of winning. Barring the most extreme and implausible of unforeseen circumstances, Democratic candidate Hillary Clinton will be the next president of the United States.

Conventional wisdom holds that it is ridiculous, and perhaps even dangerous, to say any such a thing. The primary objection is that with 11 weeks to go, too many things can suddenly transform the political landscape for any categorical statements at this stage. Moreover, it’s added, debates and other strategic opportunities will provide Mr Trump with several chances to correct his image and potentially overtake Mrs Clinton.

If one were focusing strictly on the popular vote this is plausible, although there would still be a strong basis for concluding the election is all but over. By this stage, polls are prescriptive and rarely so wildly incorrect as to produce a Trump victory. Virtually every poll shows Mrs Clinton with commanding leads nationally, in all the key battleground states, and even in several traditionally solid Republican ones.

A combination of factors might, just possibly, swing the aggregate national popular vote in Mr Trump’s direction. But that’s not how American presidential elections are decided. They are based on an electoral college system largely structured by a winner-take-all arrangement. If a given state gets 12 electoral college votes based on its population, then whichever candidate wins that state, no matter how narrowly, gets all 12 of those votes.

This means that national popular vote majorities are not decisive. The question is who can get to 270 electoral college votes winning state-by-state. The electoral college map has been shifting in recent years in favour of the Democrats. Moreover, Mr Trump’s bizarre campaign has hurt him where he needs to win most: key battleground states.

The arithmetic is clear and devastating for him. Both campaigns quietly agree Mr Trump will need to win a clean sweep of all four crucial battleground states: Pennsylvania, Ohio, Florida and North Carolina. Both agree that if he drops even one, he will certainly lose.

Mrs Clinton has clear or commanding leads in all four of these states, and, astonishingly, is running even with Mr Trump in several traditionally solid Republican states, including Georgia and South Carolina. He is not receiving the same support from white males that Mitt Romney did four years ago (indeed it seems to be slipping), and is faring disastrously with minorities and women.

It is scarcely possible to imagine that he can win all four of these states without exception, given the apparent state of the election a mere 11 weeks away (and some potentially significant absentee voting begins in late September). If Mrs Clinton had to win all four of these states, her campaign would, quite properly, be extremely nervous. Still, she could pull it off, and certainly has a much better chance to do so than he does.

But it is a very heavy lift for any candidate to sweep all four key battleground states. For Mr Trump, he will have to do it charging wildly from behind, with what everyone agrees is an insufficient ground game at the local level, campaign staff at every level, public messaging strategy, and with the profound distrust of a large majority of the public.

The reality for Mr Trump gets even more grim the closer one looks at the map. Even if he did somehow manage to sweep all four key battleground states, Mrs Clinton would still have a few paths to victory, however difficult. There are many ways for her to cobble together 270 electoral college votes. It is Mr Trump who has only one viable route: this virtually unimaginable clean sweep of battleground states.

With his campaign now being run by the de facto leader of the fringe “alt-right” cult, Stephen Bannon of the notorious Breitbart.com website – and with America’s leading racists exulting that their movement has “taken over the Republican Party” through the Trump candidacy – it’s almost impossible to imagine how the unprecedented turnaround and come-from-behind victory that he will need might unfold without a dramatic and extremely implausible “October surprise”.

Meanwhile, Mrs Clinton’s campaign seems to be growing stronger. Yet given the radical political polarisation between and homogenisation within the two American parties, it’s unlikely that she can achieve an old-fashioned, two-thirds majority landslide in the manner of Franklin D Roosevelt, Lyndon B Johnson or Richard Nixon. Those days are gone.

Pundits hedge to avoid possible embarrassment. The media needs the illusion of a competitive race to maintain interest. Therefore, few are willing to state the virtually incontrovertible truth this clearly: Mr Trump now requires not a minor political miracle to win, but an unprecedented and virtually unimaginable one. It’s over.

No wonder there’s so much speculation that he is really preparing to join with Mr Bannon and another close ally, disgraced former Fox News chief Roger Ailes (recently ousted for sexual harassment), to found a new right-wing extremist media empire. Since Mr Trump is now almost certain to lose, the self-styled “king of debt” might as well try to monetise the debacle.

Hussein Ibish is a senior resident scholar at the Arab Gulf States ­Institute in Washington

On Twitter: @ibishblog