Two years and 20 candidates later: how the 2016 campaign tore up the rulebook

While Sanders and Trump focused on Americas economic divide, Clinton spoke of its social unity. Stronger Together was a campaign slogan that sounded empty at first, but more and more powerful as her Republican opponent sought to rip civil society apart.

There are many what if scenarios to ponder. What if vice-president Joe Biden had not been derailed by the death of his son Beau and had decided to run as a populist with experience? What if Sanders had given a damn about those emails? What if either Trump or Clinton had been up against a candidate with more natural charisma a regular politician?

But early encounters with voters in 2016 quickly made clear this was anything but a regular election.

A tumultuous primary season

In Iowa, traditionally the first state to pick nominees, the caucuses proved the biggest shock to Democrats. Sanders was to lose to Clinton by a whisker, providing an early indication of her difficulties with white working-class voters.

Trump got off to a slow start in Iowa thanks to the evangelical appeal of Texas senator Ted Cruz, but by the time the Republicans got to the next vote, in New Hampshire in February, the anti-establishment revolt was in full swing. Sanders and Trump were to win there by record landslides that continued to worry the Clinton campaign up until the general election.

Super Tuesday on 1 March provided much stronger territory for Clinton, who took an ultimately unassailable lead over Sanders by cleaning up across the south. She and Trump won seven states each that night, and the nomination race looked over for each party.

There were still surprises to come, some with further potential bearing on Clintons vulnerabilities in a general election. Michigan was the biggest shock, pointing to the anger in the industrial midwest over trade policy. Wisconsin and Colorado were other states where Sanders would continue to raise the hopes of his supporters and the eye of Republican strategists come November.

But Clinton also demonstrated her strength in diverse, prosperous, metropolitan America. Her wins in New York and California finally extinguished the Bern and showed the power of the multi-racial coalition built up by Democrats. Neither Green party candidate Jill Stein nor libertarian Gary Johnson would gain much traction against such a polarising pair of candidates in the months of bitter slogging that followed the primaries.

When things looked bleakest for Trump, he would turn abroad for inspiration. He visited Britain the day after it voted to leave Europe to align himself with the mood of rebellion and invited UK Independence party leader Nigel Farage to campaign with him in Mississippi. He would travel to Mexico to try to prove statesmanship, and developed a bizarre affinity with Vladimir Putin that would lead some to suspect Republicans had nominated a modern-day Manchurian candidate.

Trumps authoritarian streak was most visible during the Orwellian-sounding Republican convention in Cleveland where he proclaimed himself the law and order candidate. His wife Melania brought ridicule to the ominous proceedings by plagiarising a speech of Michelle Obamas, while Cruz, who did not endorse Trump in his speech, revealed just how deep the rift had become with mainstream Republicans.

Clinton had the finest hours of her campaign in Philadelphia a week later, basking in the spotlight as the partys first female nominee and sharing the glow of stellar speakers such as the real Michelle Obama and their two husbands.

The partys two chosen running mates Mike Pence and Tim Kaine receded far into the distance in the face of such larger-than-life personalities. Only their vice-presidential debate was to provide a rare moment of normality during a trio of menacing encounters between Trump and Clinton.

Despite accusations that TV networks had given Trump too much unquestioning airtime, newspapers showed their investigative mettle. The New York Times convincingly demonstrated how little tax Trump had paid in the 90s, and the Washington Post unearthed the infamous recording of him bragging of grabbing women by their genitals. The Guardian revealed that these were not just hollow boasts, interviewing the first alleged victim who claimed he had done just that and foreshadowing a string of damaging sexual assault allegations. Internal Democratic campaign emails obtained by WikiLeaks also created both heat and light, but the website was accused of aiding and abetting a Russian hacking operation.

Yet it was the FBI that was to play the most controversial role, revealing at the 11th hour the existence of further Clinton emails found on the laptop of the disgraced husband of her confidante Huma Abedin. Some say the bureau was stung into action after allegations that Bill Clinton had sought to interfere in earlier investigations by meeting with US attorney general Loretta Lynch. Others, including Obama, accused it of improper leaks. Insiders revealed a culture of distrust for Clinton in a conservative-leaning organisation one told the Guardian was akin to Trumplandia. Just over a week later, FBI director James Comey told congressional leaders the new emails have not changed our conclusion that she committed no criminal wrongdoing.

None of it compared with the shocking revelations that clouded Trump throughout. Some even wondered if he was going out of his way to sabotage a campaign that had only ever been intended to promote his business interests. But as he headed into the final days of the campaign almost drawing level with Clinton in the polls again, many Democrats worried whether the electorate had grown numbed to his outbursts. They have had to wait until election day to discover whether voters would reject the bombastic populism and embrace a Madam President, or opt to make history in another way.