BISMARCK’s observation that “politics is the art of the possible” is as concise a definition of Realpolitik as one could want. But even starry-eyed idealists who sneered at the notion as opportunistic, Machiavellian and unprincipled must now wonder whether there was something to be said for getting some of what you wanted from a political party, even if no one got everything on the wish list.

That now looks like starry-eyed idealism itself, because a casual glance at all of today’s political parties suggests that none of them is offering anything that anybody wants, that none of them is offering the policies that their traditional support might expect, and that none of them shows even the minimal competence necessary to deliver what they are offering. For the purposes of this article, I am ignoring the Greens, just as 97 per cent of the electorate does.

Take the Liberal Democrats, who have just had their annual conference, in which we were promised an “erotic spasm” during Sir Vince Cable’s speech. What the 143-year-old Sir Vince actually came out with was an “exotic spresm”, which may go some way to explaining why 39 per cent of his own supporters think he’s a dud.

Of course, the Liberal Democrats, with their mania for government intervention, regulation and a European superstate, and intolerance of traditionalist views, tobacco, sugar, petrol and any other non-vegan pursuits, haven’t been even remotely liberal since the days of Jo Grimond. Now, with their backing for a “People’s Vote”, they’re followed that logic to its natural conclusion by not being at all democratic, either. If you fancy a good (hollow) laugh, look up the numerous clips of Nick Clegg before the referendum assuring everyone that there would be no second chances or votes, and that it would be a once in a generation decision, the result of which he would fully support.

Leaving that aside, it seems baffling that the party is not hoovering up what everyone seems to think is a huge, under-represented chunk of the electorate. Even if they’re not (now) in a majority, almost half the population don’t want Brexit, and the LibDems are the only UK-wide party with a manifesto that opposes it.

They ought also, one might have thought, to be drawing in the disaffected centrists that everyone keeps assuring us make up the decisive part of the electorate – what was once called “Sierra Man”, or the kind of people who loved Tony Blair until Iraq. Yet their polling is at 10 per cent or less; worse than that, a Sky Data poll on Tuesday suggested 43 per cent would rather vote for a hypothetical new centrist party than the LibDems.

In Scotland, of course, we have the other option for those who aren’t tribal Tory or Labour voters. But you’d need to be fairly long in the tooth, or past the point when you have any left, to remember the days when the SNP – except for the then tiny minority obsessed by independence – were a “none of the above” option on the ballot paper. It’s now not only the largest political party in the country, but has been the official opposition or the government for the whole of this century. And more than a decade in power has led – as it does with all governments – to widespread dissatisfaction with performance.

And the SNP’s record is, by any measure and in almost every area, pretty poor. In education, Scotland is the worst performing, and most unequal, country in the UK; healthcare spending is the highest, but waiting lists longer and life expectancy two years less; while the number of people in absolute poverty has risen steadily. That’s before one even gets to what’s laughably called its economic policy.

But if it is not competent in government, nor is it fulfilling its primary purpose. The party’s own Growth Commission report earlier this year indicated that public spending would have been lower and austerity worse in an independent Scotland, while Brexit, rather than strengthening the case for another independence referendum, actually seems to have undermined it. So the party hasn’t, at the moment, much to offer even those who have a sort of religious conviction that independence is the solution to all problems.

A similarly cultish attitude is the hallmark of the Labour Party under Jeremy Corbyn’s leadership. To the despair of many traditional Labour voters and for that matter MPs, the UK’s main centre-left party has become an intolerant clique run by Marxists, racists and apologists for terrorists, who take Venezuela – now in the grip of famine, malnutrition, mass emigration and inflation approaching 1,000,000 per cent – as their economic model.

The Corbynistas are so zealous that they suffer from the opposite of paranoia, imagining that the electorate shares their blind adulation of their leader. But not only is there no sign that swing voters prefer Mr Corbyn to Theresa May (the reverse), but many longstanding Labour supporters cannot bring themselves to support him. It’s not just that they think a Corbyn government would be economically catastrophic (though they do think that), but that the views of those who now control the party are fundamentally indecent, intolerant and antidemocratic.

And yet a neo-Marxist government under Mr Corbyn is a possibility, because of the thorough uselessness of Theresa May, who may very well be the most inept Prime Minister we have ever had. She has managed to appal not only those who thought Brexit would be a disaster, but those who thought it would be wonderful but reckoned without her ruling out numerous possible approaches in favour of one – the Chequers “plan” – which no one except her likes or thinks workable.

Opposition to the Prime Minister is, if anything, more widespread among Tories than the general population. More than two-thirds of members want her to go immediately, while the website Conservative Home now conducts surveys on who should replace her, rather than bothering to gauge whether she has any support.

That seems a perfectly reasonable position for Tories to take, since there’s nothing discernably conservative about the current Government, which has increased spending, taxation and regulation – without any of the concomitant benefits one might have expected, such as basic improvements in public services.

No matter where you stand politically, there is now no one fit to elect. I may have to rethink my dismissal of the Green Party.