Hillary Clinton looks as though she's struggling - but with Obama's support she will succeed in the end

25 per cent of Sander's supporters claim they would note vote for Hillary in the Presidential election - but history shows that this is unlikely to be the case

Hillary Clinton's predicted 2.5m popular vote margin will count for nothing (AP)

It’s not easy, but let’s try and take the longer view of the American presidential race. The next week or two will be tough for Hillary Clinton. After winning in Indiana last Tuesday her rival Bernie Sanders is probably off on another mini-streak of primary victories, in West Virginia, Oregon and elsewhere.

They’re smallish states which won’t change the big picture, that Sanders has virtually no hope of catching up to Clinton in pledged delegates, let alone of winning over the unpledged super-delegates who also vote at the Democratic convention, and overwhelmingly back the former Secretary of State. But they’re bad news all the same for the near-certain Democratic nominee.

They mean time spent fending off attacks by Sanders, time that could have been better used going after Donald Trump – and more embarrassing evidence of the trouble she has connecting with her party’s liberal wing and with younger voters. Right now, 25 per cent of Sanders supporters tell pollsters they will never, ever vote, for Clinton in November.

Then there are those emails. According to reports, she is likely to be questioned by the FBI on whether she broke the law by dealing in official classified information on her private email server. Chances are, neutral experts in these matters say, no charges will be pressed. But merely having your name and the FBI in the same headline is bad enough.

And finally to Trump himself, as he basks in his unexpectedly sudden and comprehensive triumph. With Clinton otherwise engaged, he now has the opportunity of appearing more “presidential”, softening his image and trying to patch up the raw wounds of the Republican Party of which he is now de facto leader. And who will he choose as vice-president? That’s a far more compelling storyline than the twilight meanderings of an overlong primary season.

But now take a deep breath and consider the longer view. First, those 25 per cent of Sanders voters who vow never to support Clinton. Just eight years ago she was on the losing end of an epic primary battle with Barack Obama (which also continued until June, although the outcome had been clear for weeks beforehand).

At the same Indiana primary in 2008 (which she won by a whisker) no less than 50 per cent of Clinton voters said they would never support Obama. That November Obama won the election by a country mile, backed one can be sure, by the vast majority of Clinton voters. The same, you can be sure, will happen this time. Are Sanders voters, young, liberal and idealistic, really going to shun the polls or, worse still, switch to Trump?

However deeply divided they may be, parties tend to paper over the cracks for the duration of an election season. None in recent times have been as divided as today’s Republicans, and Paul Ryan, currently the country’s most senior elected Republican, is the first House Speaker in a century not to instantly endorse his party’s presumptive nominee.

But the strong odds are that he and Trump will at minimum find a modus vivendi by the time the Cleveland convention rolls around. A first round of peace talks indeed are scheduled for Thursday in Washington. And just as Republicans will find a union of sorts to avert the nightmare of a Clinton restoration, so will Democrats come together to keep Donald Trump out of the Oval Office. Doubtless there will be some Sanders dead-enders – but nowhere as many as the Republicans who refuse to vote for Trump.

Politics can change overnight – but rarely as a result of an instant reappraisal of a candidate. Almost always it is an event, as Harold Macmillan used to say, that reshuffles the cards. America 2016 is no different. A shock revelation about Trump, an FBI indictment of Clinton, a major terrorist attack in the US – any one of them could turn calculations on their head, as could a sudden tumble in the popularity of President Obama.

Obama? He’s a lame duck, I hear you say, the guy who’s leaving the stage: what impact could he have on the outcome of the election? A good deal, it so happens. Remember 2008, when the outgoing George W Bush was so unpopular he was kept away from that year’s Republican convention? For any Republican in a close race that year who appeared with him, Bush would have been the kiss of death. Hillary however has wrapped herself in the mantle of Obama, and the gamble is paying off.

Obscured by the Sturm und Drang surrounding Trump (but perhaps thanks to it) Obama’s approval rating has climbed to over 50 per cent, more than even the sainted Ronald Reagan at a similar moment in 1988. As such he’s someone a Democratic candidate wants to be seen with, and Obama has made it as clear as he decently can that Clinton is his preferred successor.

The 2016 conventions will present a glaring contrast. Trump is being shunned by both living Republican presidents, Bush 41 and Bush 43, who refuse to endorse him. In Philadelphia, on the other hand, Clinton will have the enthusiastic backing of not one but two popular Democratic ones: Obama and of course husband Bill, whose favourability rating stands at around 55 per cent.

Yes, 2016 was when angry Americans turned against the establishment, embracing populists like Trump and Sanders – and by definition no one embodies the Washington establishment like a former president. But if that president is popular, his bully pulpit survives.

Hillary Clinton is not the greatest of candidates, for well-known reasons. She’s cautious, glib, and uninspiring on the campaign trail. She bows a little too obviously to the prevailing winds. Right now she’s facing a rough patch. Nonetheless she still leads Trump by streets in the polls, despite the media’s interest in making the contest closer than it really is (you can’t keep ratings up by selling a foregone conclusion for six months straight). Take the long view in other words, and the Clinton sky is pretty bright.