Barack Obama’s return to the campaign trail last week was a delight for Democrats, not to mention journalists, who thrilled at the spectacle of the ex-president breaking with tradition and bashing the incumbent White House occupant on a national stage.

As theatre, it was terrific. As a Democratic campaign strategy, it’s a loser.

Mr Obama is more than a gifted politician; he was a singular electoral phenomenon, so unlike other pollies as to be almost incomparable.

His background, his demeanour, his path to power were recognisable enough, but his rise to the presidency felt like destiny, the alignment of circumstance upon this particular individual. He was a man of that moment, a convergence of his talents and a yearning for something nobler than what we’d had for the previous eight years.

It’s that singularity, paradoxically, that helps explain why some people who voted for Mr Obama twice could then vote for Mr Trump. Back in 2008 and again in 2012, they weren’t voting for a slate of Democratic policies – universal health care, leaving Iraq, climate change, whatever – but for a guy with a smile and an approach that felt right for the times. They trusted him, they liked him – at least more than the guy running against him.

Mr Obama famously went kitesurfing with Richard Branson in 2017, soon after leaving the White House. The waves might be a better place for him during the midterms. Photo: Getty

Then, for very different reasons but with the same logic, enough of those people pulled the lever for Mr Trump.

It has been a forlorn two years for many. A T-shirt I saw in a shop on Cape Cod in Massachusetts last weekend showed a grinning Obama with the words, “Miss me yet?” A New York magazine cover this summer pleaded, “Barack Obama, Where Are You?”

But this pining gets in the way of some uncomfortable facts. Mr Obama’s distinctiveness was great for him at the polls, but it never translated into advantages for other Democrats.

They lost control of Congress just two years into his presidency and never gained it back. He never took charge as the leader of the party, working to seat mayors or governors around the country or to bolster the party’s bench of candidates. Despite his charisma, Mr Obama was uninterested in the hail-fellow stuff of politics, the schmoozing that Joe Biden and Bill Clinton excelled at.

That became clear in 2016. Mr Obama, who’d soundly defeated Hillary Clinton in 2008, now realised he had to campaign hard on her behalf.

In the final weeks of the campaign, he barnstormed the country on her behalf. “Everything we’ve done is dependent on me being able to pass the baton to someone who believes in the same things I believe in,” he told a radio interviewer just weeks before the election.

One of the T-shirts pining for the former president. Photo: Redbubble

We know how that worked out.

So now comes the former president, breaking with custom, and taking on the corruption, ugliness and dishonesty of the Trump administration.

“We’re supposed to stand up to bullies, not follow them!” he thundered, thrilling the students at the University of Illinois, his home state.

It was fine stuff, if a bit predictable, full of history and concern, a stout belief in American institutions, a sprinkling of blame onto both parties but also a full indictment of the Republican party and its cowardly support of Mr Trump’s reign.

I couldn’t help but watch Mr Obama and feel he was atoning for 2016.

But Democrats don’t need to refight the last election, and bringing Mr Obama back onto the stage reframes this as a rematch. That’s how Mr Trump sees it, and the media duly pounced on the confrontation.

In their hearts, Democrats always wanted 2016 to be Obama v Trump. Alas, US law doesn’t allow it, and wishing it so doesn’t make it worthwhile. Nostalgia won’t win this midterm election, which is about turning Congress from red to blue.

Charles Blow, a New York Times columnist, said he was glad Mr Obama was back if only to push Mr Trump out of the news. Bad idea.

Mr Trump needs to be in the news as much as possible, if only to fully examine his poisonous behaviour. Turning the spotlight back to Mr Obama feels like all the reboots of all the old programs now clogging American TV: exciting at the outset, then increasingly unsatisfying in the following weeks.

Democrats don’t need to go back in history to find their future. They tried that with Mrs Clinton in 2016. The alchemy that was Mr Obama’s triumph in 2008 can’t be recreated.

Around the country this year, new faces with new voices are articulating Democratic alternatives, working their way out of the ashes of the last election debacle. Some are centrist, many are more radical. Almost all are unknown to a national audience, but they’ve persuaded enough of their neighbours to come out and put them on the ballot. And most don’t speak Mr Trump’s name. They don’t have to; they know he’s the enemy. They’re focusing on alternatives, not just anger.

Democrats seem energised, if a little giddy about their chances. They don’t need a beloved ex-president to tell them what they’ve seen with their own eyes during the past two years. We know how Mr Obama feels about Mr Trump; we feel the same way.

Relying on Mr Obama, if only for a few speeches, pushes aside the new candidates fighting for the future. It says the party isn’t ready to move past their singular former leader,  and it delays the hard work of finding new standard bearers for the party.

Now, if Michelle were interested …