WHENEVER I see or hear of Barack Obama these days, there’s a terrible double-take that happens inside me.

No matter the occasion, the tall, calm, handsome figure remains a consistent presence. A mixed-race statesman-scholar, measuring his words carefully, bringing the frantic world of hypermedia down to his own thoughtful pace. If you wanted traditional top-down power to look and sound any more authoritative in 2016, it would be hard to beat the US President.

And then, instantly, I think of this figure at his desk in the White House every Tuesday, approving names and locations from a terrorist “kill list” in Pakistan, Yemen and Somalia, the assassinations effected by drone technology. By the beginning of 2016, according to NGOs cited by the New York Times, Obama had approved 506 strikes, which had killed 3,040 terrorists and 391 civilians.

You don’t need to web-search very much to find on-the-ground horror stories of family innocents blasted to fragments, or left with sickening injuries. A generation in these territories who literally can’t trust the skies above them; for whom America represents random, sudden death, an opportunity for “blowback” and retribution. While elsewhere in the White House, his own beautiful children frolic, thrive and safely grow.

Another double-take: It’s easy to glory in the cultural legacy of Obama. Particularly as fragments of it are so easily available online. As a musician, you look at the pantheon that’s performed at Obama’s White House concerts – Stevie Wonder, Tony Bennett, Smokey Robinson, Elvis Costello, Bob Dylan, James Taylor, Aretha, Franklin, Jack White, John Legend, Herbie Hancock, BB King…

Or take his own drop-dead humour. Obama’s monologues at the White House Correspondents’ Dinner over the last eight years are a demonstration of male coolness that takes the Sinatra Rat Pack era to a different level. Try and catch the CBS Tonight show clip ‘Slow jam the news with Barack Obama’. It’s a dude’s soul party anyone would want to be invited to – which also manages to deliver Obama’s chosen highlights of his two terms in office.

And then you remember. How do we cope with the fact that the two major societal responses to an Obama presidency have been a rise in white nativism, beginning with the Tea Party and ending with the orange-tinged fulminations of Donald Trump? And the corresponding birth of Black Lives Matter, the first major anti-racist movement in the US since the 60s, responding to an epidemic of police violence against African-Americans?

Obama began as what was termed by pundits the Narrator-in-Chief. He took the opportunity of his presidential “bully pulpit” to try to make the case for a post-partisan politics, or redefine America’s profile as a world power.

But as mass shooting after mass shooting racks the nation, it’s been painful to see Obama’s public eloquence turn to a passive, tearful despair. How do you “frame” and “tell a different story” about the sheer inability of American lawmakers to reign in mass gun ownership in their society?

In 2015, when Obama began to sing Amazing Grace at the Charleston memorial service for the Emanuel African Methodist Episcopal Church, where nine people at worship had been killed by a young white man, the sight and sound of it was both electrifying – how can a politician be so connected to the emotion of a moment? – and disheartening.

How can black Americans still be gathering together in the not-so-safe havens of the gospel church, still mourning their dead? This was a spectacle both of presidential power, and of its powerlessness – indeed, perhaps even marking a reverse.

But as many of my friends and comrades over the years have often warned me: “You’re putting too much faith in one American leader. By the time he got there, Wall Street and the capital markets were fully placated, the military was completely reassured. Nothing can ever fundamentally change the direction of American empire, commercially and militarily.”

Surveying the various news articles on his policy, it’s true that – once the Republicans made clear that “bi-partisan” action was a fantasy – the Obama administration has mostly advanced though power directed from the Presidential office itself, bypassing the now Republican Congress and Senate.

Earlier, Obamacare squeaked through Congress (with no Republican votes), giving 20 million people access to quality health care, bundled in with an act that will mitigate long-term student debt. But many other changes have come from playing what a recent article calls “the inside game”.

Obama still does at least control “the executive branch, the vast bureaucracy responsible for the actual workings of government”, writes Politico’s Michael Grunwald. “He couldn’t pass a law requiring employers to provide paid sick leave, but he did issue an executive order requiring federal contractors to do it.” (Anyone reminded of the Scottish Government’s promotion of the living wage, by first paying it to its own public employees, put your hand down).

Similarly, one per cent of the nation’s energy budget has been improved by tighter environmental regulation on… air-conditioners. The Hoover Dam it ain’t.

The Obama record on climate change is respectable – the Keystone Pipeline cancelled, its solar energy industry boosted, and thus enough credibility to help broker the Paris deal (though fracking is a major blot). But it’s not the soaring rhetoric of 2008, where “this was the moment when the rise of the oceans began to slow and our planet began to heal”.

But then, I wonder whether soaring, idealistic political rhetoric is a growing casualty of our hyper-vigilant and net-empowered age – and for me, this is part of the poignancy of the end of Obama’s second term. The Martin Luther King phrase “The arc of the moral universe is long, but it bends towards justice” was used a lot by Obama in the last few years (he usually replaced “moral universe” with “history”).

Now if this arc is so implacable, you might imagine that one historic candidate might naturally follow another: The black Barack Obama, then the female Hilary Clinton. But in the era of the universal digital archive and the typed-in keyword, everyone’s record is instantly available – which can then be reassembled to fit the user’s own preferences and prejudices, and sent back out to infuriate and mobilise.

So those trying to ride the “arc of history” might eventually hit a patch so peppered with digital pot-shots that it gives way under their wheels. Hillary is so much a feature of the American establishment – one that has deregulated and destabilised its own capitalist economy in the last 30 years, and has barely learned any lessons from its wars and interventions over the last century. Will she collapse through the floor of the arc, as the campaign swings into its maelstrom stage?

Many are already lamenting the “last adult in the room”, walking out the door of his Oval Office for the last time. But I find myself harbouring ever more doubts about the saliency of presidential-style political leadership – all those charismatic “deciders” and “commanders-in-chief”.

I prefer the demeanour of the three party leaders I feel closest to in the politics of this island. Nicola Sturgeon, Jeremy Corbyn and Patrick Harvie all seem instinctively constructive and collegiate. While hardly bending on their core principles, they seek overlap and shared outcomes where they can be found. I note the SNP deputy leadership “battle” – if battle it can be called – is operating in the same, modest mode. This was, of course, Barack’s opening gambit – no-drama Obama – the serene unifier of difference and polarity. But the American experiment was tottering and toppling well before he strode into 1600 Pennsylvania Avenue. I would like to bet that he’s known that, all along. And if imperial decline is to be quietly managed, at least do it with effortless cool.