There’s a macabre and notionally scientific anecdote which you may perhaps have heard before:

If you take a frog and put it in a pan of boiling water it will immediately leap straight out again. However, if you take a frog and place it in a pan of cold water which you then very gradually heat, the frog will placidly remain there until it boils alive.

Thankfully, Wikipedia tells me that not only is the story biologically unsound but that scientists have had the good grace not to do any experiments of this type since the 19th century.

The metaphor which the anecdote provides can also be dubious: it’s frequently pulled out by rightwing conspiracists in the US when they try to claim that their nation is moving stealthily but inexorably toward socialism. But it does have some merit as an illustration of the concept of creeping normality, the idea that the world can change around us profoundly, but do it so gradually that we don’t notice. It only takes a moment’s thought to realise that this is certainly true in technology, architecture, culture, fashion, manners, attitudes and innumerable facets of life.

It can also be true of the health of our democracy.

At the general election, turnout was 66 per cent. This was slightly up on 2010, which was in turn slightly higher than 2005; it therefore notionally represented an upward trend and was reported as such.

But, as we know, close elections mean a higher turnout. The 2010 election was extremely close and 2015 was of course predicted in all quarters to be even closer.

Before that, we had a run of relatively one-sided elections where it was not surprising that many didn’t feel enthused to vote since it was clear that Labour were going to win.

Going back further, the last time that there was a really close election was 1992. The turnout then? Just under 78 per cent.

So, that’s 78 per cent turnout in 1992 and 66 per cent in 2015. That’s one hell of a drop in a quarter of a century.

Here’s my unfalsifiable assertion about what would have happened if there had been a turnout of 66 per cent in 1992. It would have been the story of that election. It would have been a cause of huge concern in the media, the civil service and all political parties. There would have been a bout of soul searching and perhaps a Royal Commission or other enquiry about how to reverse the trend.

Now, in 2015 this crisis of democracy has actually come to pass, but with scarcely any comment. The reason? Simply that it arrived in slower motion, giving us time to get used to the idea.

One worrying thing is that the trend seems likely to continue. After Ipsos MORI published its study of how Britain voted in 2015, which includes a breakdown by age, (showing that turnout for 18-24 year olds was a measly 43 per cent) there was a glib tweet from Asa Bennett, an assistant comment editor at the Telegraph, that ‘Britons become more Conservative as they grow older, and more likely to vote as people get older’. But this is not what the data shows.

We can only look at how propensity to vote changes with age by examining population cohorts over time. Inasmuch as this has been studied, there is some academic evidence that if a ‘voting habit’ is not acquired early, it will never be acquired. The evidence appears to be that non-voting is not a phase that some young people go through before gaining a sense of civic responsibility when they hit 40. Instead, there seem to be cohorts for whom voting is just something they have never done and – assuming nothing happens to dramatically change their thinking – never will.

You can, I think, see this in the estimated turnout for the same(ish) cohort in elections approximately 20 years apart. In that close election of 1992, MORI estimated that the turnout for 18-24 year olds was 63 per cent. In 2015, that cohort approximately matches up to 35-44 year olds, 64 per cent of whom were estimated by MORI to have turned out. Their turnout, in a similar type of election, has not gone up with age.

So, we can make the tentative prediction that unless something dramatic changes, only 43 per cent of the 2015 18-24 year olds will vote at future elections, as they get older.

I’ve done some very rough and ready calculations on how trends might continue in 10 years time, as the population ages and new cohorts enter the electorate. Using ONS population projections, I worked out roughly how the electorate is anticipated to break down into age groups for a 2025 Election. I assumed that particular cohorts of electors will continue to turnout in the same proportion as they did, according to the MORI figures, in 2015. So, for example: 72 per cent of 45-54 year olds turned out in 2015; I therefore assume that 72 per cent of 55-64 year olds will turn out in 2025. I’ve also, optimistically, assumed that the 18 year olds of 2025 will be as likely to vote as the 18 year olds of 2015.

All of these back-of-the-envelope calculations give me a predicted 2025 turnout, assuming a similarly close election to that of 2015, of 62 per cent. If it’s not a close election, that percentage could perhaps drop to the mid/low 50s.

If the trends continue still further, at some point in the next 25 years, we are going to have a Government elected on a turnout of 50 per cent or lower.

Possibly more worrying than the difference in turnout by age, is the variation by socio-economic group.

In 1992, 84 per cent of ABs are estimated to have turned out, compared to 77 per cent of DEs.

In 2015 this gap had opened up starkly: 75 per cent of ABs voted; only 57 per cent of DEs.

(as a reminder, the more-than-slightly archaic NRS social grades are based on occupation of the head of household:

A – Higher managerial, administrative or professional.

B – Intermediate managerial, administrative or professional.

D – Semi-skilled and unskilled manual workers.

E – Casual or lowest grade workers, pensioners, and others who depend on the welfare state for their income.)

Basically: the rich, established and comfortable are still voting in large numbers; the poor and vulnerable aren’t.

We’re at a place where big decisions are being taken about the shape of our state, our economy, our society and our environment.

About transfers of wealth between rich and poor – tax rates, benefit rates and eligibility, bank bailouts, tax evasion and avoidance.

About transfers of wealth between the generations – the housing market, pensions, care costs, childcare, education, inheritance tax).

About longterm issues like climate change, energy provision and infrastructure projects, which will affect the young far more than the old.

And yet the young and the poor are absenting themselves from these decisions in large numbers.

I have a lot of affluent, educated friends (virtually all of whom vote) and when I’m haranguing them on this subject, at this point someone will talk about apathy and how ultimately it’s up to individuals whether they can be bothered to vote. The idea of compulsory voting is often brought out as a potential solution.

The thing is though, it’s not about apathy, it’s about alienation. And low turnout is not the problem itself, only a symptom.

A couple of extended quotations from the Hansard Society’s 2014 Audit of Political Engagement are worthwhile at this point:

Two-thirds of the public (67 per cent) agree that it is their ‘duty to vote in all types of elections’ although fewer than half of 18-24 year olds (46 per cent) believe this compared to 79 per cent of those aged 65 and above."

The public’s sense of personal political efficacy continues to be stuck in a trough in the low 30s. Just 31 per cent think that if people like themselves get involved in politics ‘they really can change the way that the UK is run’. This is the joint lowest score recorded in the Audit series and compared to the position 18 months prior to the two previous general elections it is the same as that in Audit 6 (31 per cent), but somewhat lower than in the first Audit (37 per cent). Despite levels of interest in and knowledge of politics holding up or improving, the public continue to feel relatively powerless in the political process. So too they feel that Parliament, the core institution of our democracy, does not actually encourage their involvement: less than a quarter (23 per cent) agree that it does so, compared to 30 per cent who said the same in previous Audits."

A third of the public (33 per cent) think that the system of governing in Britain works ‘extremely’ or ‘mainly’ well…With the exception of the 18-24s (24 per cent), all the age groups report a satisfaction rate between 31 per cent and 38 per cent…As one would expect, the higher the social class the more satisfied with the system of governing people are. However, the scale of difference between those in social classes AB and the rest is particularly stark: ABs have a net satisfaction rating of -3 per cent; C1s score -34 per cent; C2s -42 per cent; and DEs have a net satisfaction score of -53 per cent."

And so…

…compulsory voting does not tackle the root causes of non-voting or make a sizeable difference to the quality of communication between voters and parties. Compulsory voting would have to be associated with an overhaul of the culture of a voter’s duties via an education campaign. Compulsory voting runs the risk of treating the wrong problem – poor turnout rather than any of its myriad causes."

These people, whether young, or poor, or both, are not stupid. They have just noticed that the party political system is pretty arcane and archaic, and that – whoever’s in power – it doesn’t seem to do an awful lot for them. You may think that that statement is terribly unfair to the Labour governments of 1997 – 2010 and up to a point I might agree with you. But we can’t argue with how people feel.

And, really, in the 2015 campaign, who was taking note of what these millions of alienated abstainers were saying, and actually responding to it.

It’s all very depressing. But I want to finish with two big questions.

First, at what point does this become a crisis of legitimacy?

This year, a Conservative Government was formed on the basis of the votes of 36 per cent of the 66 per cent of voting age people who turned out – disproportionately the older and better off.

If this trend does worsen; if – say – overall turnout dips below 50 per cent, what happens then? We simply don’t know because it would be completely uncharted territory.

Second, why on earth is the left in general and Labour in particular not devising an entire strategy around this situations?

It’s the young and the poor not voting, in their millions.

We know that the young and the poor on the whole lean to the left.

We also know that they’re alienated from all the parties, from the Westminster Parliament, from the system as it stands.

Surely that’s the basis of – for want of a better word – an insurrection. Why the hell aren’t any of the Labour leadership candidates talking about how they might completely change their pitch, their approach, their policies to get these people engaged and involved with politics, and voting for the change that’s needed.

Apologies if I’ve missed it, but I have heard nothing about this from any of the candidates, or from the commentariat. There has been plenty (arguably, far too much) about how to woo centrist voters. There has been nothing about how to re-engage the millions of young and poor electors who could, if listened to and given something real and positive to vote for, be natural leftwing voters.

For the moment though, we’re all still sitting in the saucepan. It’s up to us to notice that something is gradually going very badly wrong. It’s not too late to make our leap to freedom, but the water is starting to get awfully hot.

This piece originally appeared on James Elder's blog, which you can read here.