A few days ago I passed the African National Congress’s headquarters in the centre of Johannesburg.

On the side of the building hung a banner outlining the “Freedom Charter”, as adopted back in 1955. This included a series of noble political goals including equality, human rights and the right to work.

“The People Shall Share in the Country’s Wealth!” was one promise. “There Shall be Houses, Security and Comfort!” another. “There Shall be Peace and Friendship!” predicted the last.

Such sentiments, of course, were a product of the Apartheid era, when majority public opinion was irrelevant and change via the ballot box wasn’t an option. Naturally, therefore, the politics of hope sought to displace the tyranny of white minority rule.

Much of the Freedom Charter ended up being incorporated into South Africa’s famously progressive constitution, a document held up as a model by some Yes supporters during the referendum campaign. But codifying a nation’s hopes and ideals was the easy part, translating them into reality much more challenging.

As the writer RW Johnson argues in his forthcoming book, How Long Will South Africa Survive? The Looming Crisis, the ANC has in many respects failed to live up to its vision of a post-Apartheid South Africa, not least because it’s a fiendishly difficult country to govern well. “Hope” has not replaced the townships or prevented “load shedding” (otherwise known as power cuts).

All of this serves as a heavy-handed way of saying that the politics of hope rarely gives way to genuinely transformative governance. Think of Barack Obama’s bid for the White House all those years ago; he even wrote a book referring to the “audacity” of hope and outlining a broadly social-democratic programme, little of which has been implemented as he reaches the end of his second and final term.

Closer to home François Hollande promised a radical agenda if elected president, yet today France retains decades-old problems, while in Greece the hope-fuelled Syriza movement lies in tatters. And of course there’s the SNP, whose mediocrity in devolved government has been ingeniously spun into a record Franklin D Roosevelt would struggle to rival. But then they articulate the politics of “hope”, so no one really cares about trivial things like reality.

My fellow columnist Iain Macwhirter consistently argues that politics is about “morality”, although perhaps it’s more accurate to say that politicians utilise morals, like hope, to further their aims. Mrs Thatcher, for example, articulated hope that the UK could be saved from decline; Tony Blair that there existed a “Third Way” between the ideological extremes of old, and Alex Salmond that independence from the UK at least provided hope of an (often ill-defined) alternative to the status quo.

But hope, as a South African friend of mine put it, “is not a plan”. Indeed, those who practice the politics of hope often seem to regard detailed policy as a distraction, only reluctantly spelling it out when compelled to do so. For example the SNP during the referendum, faced with irksome questions from nit-picking Unionists, and the Labour leadership contender Jeremy Corbyn, upon realising he might actually win.

Talking of which, the resurgent Member for Islington North serves as a useful reminder that “hope” can be a curiously conservative political force, seeking to preserve a mythical past rather than fashion a bright new dawn. Fittingly, therefore, even Scottish Conservative leader Ruth Davidson has got in on the act, yesterday attempting to out-hope the SNP by pitching her party as “a clear Scottish alternative to the nationalist orthodoxy” in the run up to next year’s Holyrood elections, demonstrating to voters that “there’s a different, better, way to go”. Well, good luck with that.

“The mood is there and we happen to be in the middle of it,” Mr Corbyn told the Guardian on Saturday. “We are not doing celebrity, personality, abusive politics – we are doing ideas. This is about hope.” But Mr Corbyn’s “ideas” are largely boringly orthodox, while he conveniently ignores his own party’s history. As Nye Bevan remarked of ideological puritanism: “you call that statesmanship? I call it an emotional spasm.”

Thus the politics of hope is often little more than political escapism, telling voters what they want to hear rather than tackling inconvenient truths. Successful politicians – and successful governments – have always balanced idealism with pragmatism, and in office usually lean heavily towards the latter (not least the SNP). For grown-up politics involves making difficult decisions and potentially offending certain voters, conveniently the politics of hope does not.

And equally usefully, when “hope” turns out to be an inadequate response to complex political problems, there is usually someone else to blame. Preaching “hope over fear” also allows ostensibly positive campaigners to indulge in scaremongering. It’s now forgotten that President Obama secured a second term on the back of a deeply negative campaign, while in the closing stages of the independence referendum Yes Scotland also dabbled. If you vote No, they cried, the Scottish NHS will be privatised! Scotland will be ignored!

That the reality has turned out very differently is of no import, for the politics of hope hides a multitude of sins, which is why it’s highly likely the SNP will seek to keep hold of that agenda for the foreseeable future. Those from within its own ranks urging a more credible pro-independence pitch on currency and economics will therefore be humoured but ultimately ignored, for reality cannot be allowed to intrude lest the “hope” agenda be undermined.

And if “hope” does prove enough to win a second referendum, and that isn’t unlikely given the backdrop of continued austerity and increasingly strident Conservatism at Westminster, then the notion – again articulated during the independence referendum – that the SNP might disband is for the birds. Rather it would become the ANC of Scotland, the guardian of Scotland and “Scottishness”, sustaining its popularity no matter how underwhelming the reality of independence.

Parties like the SNP, the Greens and (potentially) Labour have correctly diagnosed the problem, a growing – and to an extent justified – feeling among voters that politicians are “all the same” and “all in it for themselves”, thus they offer the antithesis of that cynicism: hope. But in doing so, especially when hope isn’t adequately matched by practical policy, proponents of that sort of politics risk becoming merely a new manifestation of the same old cynical game.

Harry Reid, a former editor of this newspaper, once accused me (in a nice way) of being overly “utilitarian” in my analysis of politics, too concerned with practicality and dismissive of the vision thing. To this I’ll happily plead guilty as charged. Of course I can see, as Harry argued, that “hope” has a place in politics, but it’s rarely enough – particularly in the midst of economic and political flux. Hope, to quote my South African friend again, is not a plan, and modern politics badly needs a compelling plan of action.