Donald Trump has always been obsessed with his predecessor and polar opposite, Barack Obama. It was therefore perhaps preordained that, barring a political sensation, he will likely have to fight for re-election against Obama’s former right-hand man.

Joe Biden appears to be running away with the Democratic primary race after he beat Senator Bernie Sanders in at least three states on Tuesday including Michigan, which had been billed as make-or-break for his opponent. Once again it was the former vice-president and establishment favorite Biden, not the Vermont democratic socialist Sanders, who boosted turnout.

Voters showed that above all they yearn to turn back the clock and default the country back to factory settings

After 10 debates, millions of dollars spent and countless rallies and town halls among two dozen candidates, Democratic voters showed that above all they yearn to turn back the clock and render Trump a four-year aberration. They are looking to default the country back to factory settings.

Progressives had argued this would be a fallacy, that the America of 2016 contained the seeds of its own destruction and that ultimately, Trump is a symptom of dysfunction rather than a cause. But the party’s disciplined coalescing around Biden suggests trying to put the genie back in the bottle was irresistible.

The push for a third term of Obama did not work out so well in 2016, when his former secretary of state, Hillary Clinton, lost to Trump. There were clues in Tuesday’s results that suggest Biden can do better – but other reasons to think his flaws as a candidate might be even greater.

Seemingly down and out just a month ago after beatings in Iowa and New Hampshire, Biden powered through South Carolina and Super Tuesday states like a juggernaut, apparently in spite of weak performances and his campaign team rather than because of them.

That set up Tuesday as a replay of the 2016 primary, with Biden stepping into Clinton’s shoes and Sanders reprising his own role. But whereas Sanders won Michigan that night four years ago, gaining fresh impetus for months of bitter fighting, he was on course to lose it by double digits on Tuesday. He was also down in Missouri and, as expected, was crushed in Mississippi, having never worked out how to appeal to African Americans.

Voters appear to have bought the centrists’ argument that Sanders would suffer the same fate as Labour’s Jeremy Corbyn in Britain. Even in early states that he won, Sanders failed to expand his base compared with four years ago, except among Latino voters. In Michigan, exit polls say, Biden won black voters 66% to 29%.

In Missouri, among white voters without college degrees, CNN exit polls found Sanders had beaten Clinton 64% to 36% in 2016, but in 2020 Biden beat Sanders 60% to 33% – a massive swing. This much mythologized group – the subject of endless journalistic “safaris” in the midwest – were a critical constituency for Sanders against Clinton. They also provided a warning for how Clinton would fare against Trump. There are three likely reasons why Biden performed much better among them.

One is that they may have been driven by anti-Clinton sentiment in 2016: their vote for Sanders was not so much about him as a protest against her. Another is that the stakes are different this time: the nightmare of the Trump presidency has instilled pragmatic urgency, whereas in 2016 it was merely a fanciful possibility.

Third, there is Biden himself. His manner can be earthy, pugnacious and unpolished, different from the elitist New York image that dogged Clinton. Long before this election cycle began, pundits were speculating that the straight-talking former senator from Scranton, Pennsylvania, would have done better at appealing to blue-collar voters.

Unlike Clinton, fairly or otherwise, Biden is seen as having that magic elixir: authenticity. And as with Trump, his gaffes only seem to prove the point.

The Democratic primary is not over yet. This election has had many twists and turns. But with states such as Florida and Georgia voting later this month, things are likely to get worse for Sanders rather than better. The coronavirus outbreak is causing rallies to be cancelled, denying Sanders crucial oxygen while protecting Biden from gaffes and scrutiny. Ominously, Sanders spent Tuesday night back in silent retreat in Vermont, while Biden gave a speech that observers praised as presidential.

Republicans will dust off the playbook used against Clinton

But in their rush to unite and desperation to beat Trump, Democrats risk overlooking their new champion’s obvious flaws.

Association with Obama can be an asset to one side of America but a dog whistle to the other. Republicans will dust off the playbook that was used against Clinton: Biden as establishment figure or, to put it another way, swamp creature. Instead of Bill Clinton’s alleged corruption and womanizing, it will be Biden’s son Hunter’s alleged corruption and womanizing.

And instead of Clinton’s gender, it will be Biden’s age. At 77, he is four years older than Trump and would be the oldest US president ever elected. He does not wear it lightly, with verbal slips that seem to be coming thicker and faster than ever. And he remains dangerously unpredictable.

Touring an assembly plant on Tuesday, Biden was accused by a construction worker of wanting to take away people’s guns. Biden replied: “You’re full of shit.” As the worker argued, Biden snapped: “Don’t tell me that, pal, or I’m going to go outside with you, man.” The worker objected: “You’re working for me, man!” Biden retorted: “I’m not working for you. Don’t be such a horse’s ass.”

It is hard to imagine Clinton ever having such an outburst or, if she did, ever being forgiven for it. So Biden v Trump, if it happens, will not quite be the same as Clinton v Trump. But Biden and Clinton do share one inescapable burden: they’re no Barack Obama.