A fundamental, although little- documented, change is happening in the way developed Western societies now relate to political parties. It is a shift which hollows out the competitive system of politics and elections we knew, without replacing it with anything which is either stable or substantial.

The basic reason for this hollowing-out process is the reluctance of electorates throughout the world to engage in organised politics. Britain's Labour Party, to use just one example, used to have a membership of one million in 1945. But this went down to 400,000 by the late 1990s, and to no more than 190,000 members before the current party leadership elections.

An even more spectacular drop in membership has been registered for the Conservatives, the other of Britain's top two parties: They had an astonishing 2.8 million members in the early 1950s, went down to around half a million in the 1990s, and now have fewer than 150,000 members. Either way, not more than 1 per cent of the total British electorate is active in party politics.

It's worth pointing out that party membership is pretty much in decline across Europe. Italy's ruling Democratic Party has lost 100,000 members over the past year alone. And in Germany, both the Social Democrats and Chancellor Angela Merkel's Christian Democrats are losing around 3 per cent of their paid-up members each year. And a new generation of Germans seem to reject politics altogether: Only 4 per cent of Dr Merkel's ruling party are aged 30 or under.

VOTERS' POLITICAL APATHY

The same trend is observable in the US where, peculiarly, people have to register their party affiliation when they put their name down in the electoral roll; that does not preclude voters from marking their ballots in any way they wish, but does give an indication of initial political engagement, and is one criteria in deciding who can vote in the primaries, which select each party's presidential candidate.

The number of those who claim to be independent, that is not leaning to either the Democrat or Republican Party, was 29 per cent of the total US electorate in the late 1980s. It is 42 per cent of registered voters today, a peak never previously encountered in the history of American politics.

New political movements can attract large numbers of enthusiastic supporters, but "in catch-all parties, membership is no longer an identity badge that reinforces membership in a distinct community", argues Professor Susan Scarrow, who chairs the politics department at the University of Houston in the US, and has written extensively on the topic.

"Parties can still offer selective economic and social benefits, but the real and relative values of these has waned, due to changes in patronage opportunities and due to changed social circumstances," she adds.

One result of this dwindling membership trend is that, with the exception of countries like Germany where parties are funded out of public funds, most other parties are even more reliant on single rich donors. Such a dependency has its implications: it's not by accident that political parties in Britain and France - to name but two big European countries - seem to be staggering from one financial scandal to the next.

Parties have sought to attract new members by offering them a bigger say in how the organisation is run, or by encouraging a wider interaction in policymaking. It is an interesting paradox that, when Western political parties were genuine mass movements, they did not care much about the democratic character of their internal decision-making but the moment they started to shrink, internal democracy suddenly assumed importance.

Britain's Conservative Party leaders used to be elected exclusively by that party's MPs; the membership at large was only asked to applaud the outcome. Meanwhile, Labour's leaders were picked by a handful of middle-aged, overweight trade union bosses usually wearing polyester kipper ties and charitably known as the "men in grey suits".

The same used to happen in the US, where party bosses - always men, almost always white and almost always smoking - would get together in "smoke-filled rooms" to decide their presidential candidate.

All this has gone. In almost all Western nations, members vote directly for their party leaders. And in the current contest, Britain's Labour Party has introduced another innovation: In return for a small membership fee of £3 (S$6.50), anyone can join the party and get an instant right to vote for the party's next leader.

DISCONNECT BETWEEN POLITICAL CLASS AND MASSES

While it can be argued that greater internal political consultation is to be welcomed, it also has some perverse outcomes. The first is the rise of the professional politicians as party leaders. It is instructive that the last British prime minister who had a career in any trade or profession before entering politics was Mrs Margaret Thatcher, who came to power in 1979; all the subsequent British premiers have been in politics since leaving university and have tried to acquire a "normal" trade only after retiring from politics.

The same applies to the US: The Bush and Clinton families, which have ruled the country almost uninterrupted since the mid-1980s. The disconnect between such a professional political class and ordinary people has never been greater.

But the latest and far more serious outcome of the shrinking membership base of existing political parties is the rise of today's fringe politicians - of people such as Mr Corbyn or Mr Trump. They cater to an increasingly narrow band of committed people who still bother to pay their party membership dues and want to have their prejudices confirmed.

The people who support Mr Trump thoroughly approve of the billionaire property tycoon's narcissistic personality, of his misogynist dismissal of women and of his characterisation of all immigrants from Mexico as "criminals, drug-dealers and rapists".

An opinion poll published in Britain over the weekend revealed that over a quarter of those who supported Mr Corbyn's bid to become Labour leader and Britain's potential future prime minister believe the world is run by a "secretive elite" which needs to be destroyed.

A good case can be made that if established political parties want to commit collective suicide, they should be free to do so; there would be other parties to take their place.

However, the reality is that the mantle of existing parties is not being taken up by other movements with the organisational skills to offer a different government vision, but rather by a gaggle of one-issue protest movements of various shapes and formats.

In short, the demise of existing parties may not result in a regeneration of the political landscape in the West, but in more desolate and fractured politics.

Which is why the rise of the Donald Trumps and Jeremy Corbyns is no laughing matter. For their ascent represents the failure rather than the rejuvenation of existing politics.

And they call into question our way of thinking about Western political parties as the linkage between the public and institutions of government.