It may not be a fashionable sentiment, but this may be an appropriate time for us to pay sympathetic consideration to the hard lot of the politician — for our own sake, if not for theirs.

Practitioners of the art have just suffered mass layoffs in Western Australia, where 24 out of 89 members seeking re-election were turfed out last Saturday by an increasingly capricious electorate.

Labor now finds itself with a team that’s almost too big for the parliamentary party room to accommodate, but recent history suggests they shouldn’t get too comfortable.

While the scale of Labor’s win is without precedent in Western Australia, it forms part of a clear trend in the national context that raises questions about the ongoing suitability of Australia’s prevailing electoral and constitutional arrangements.

The trend in question is illustrated in the chart below, which shows two-party swings at every mainland state election since the mid-1980s.

The series of defeats suffered by state Labor governments in the late 1980s and early 1990s seemed extraordinary enough at the time, but they have been put in the shade by what voters have had in store for governments on both sides of the fence over the present decade.

Saturday’s result was the fifth time going back to 2011 that a swing exceeded 10% — and you can make that six if you include the Tasmanian election in 2014, which is not included because its Hare-Clark electoral system does not allow for a cleanly determined two-party swing result.

No doubt many would think the victims of these results got no less than they deserved, but there are good reasons why such enthusiasm should be restrained.

Single-member electorate systems, which are characteristic of the British tradition, are noted for producing blowout results in favour of the party with the highest share of the vote.

With the electorate apparently containing increasing numbers of swinging voters who stampede in the same direction, this is leading to ever more lopsided results.

For all Labor’s very considerable achievement in Western Australia on Saturday, it still registered (on latest numbers) only 42.2% of the primary vote — less than Gough Whitlam managed when he led Labor to its historic disaster of 1975, but in the current environment, good for a thumping majority and monopoly on executive power.

Once the euphoria wears off, McGowan’s government will face the challenge of keeping out of mischief its bloated contingent of backbenchers, which includes a few dumped members of the former shadow cabinet.

This is, admittedly, not a bad problem to have compared with the one faced by the Liberals and Nationals, who must now spread a workload of shadow ministry and parliamentary committee roles among a dramatically depleted line-up.

But there’s another concern raised by the result that’s not quarantined to one side of politics.

It’s the example that’s been set to anyone contemplating a parliamentary career, who must reckon with the fact that there’s scarcely such a thing as a safe seat any more, and that even routine swings of the pendulum can bring all their hard work crashing down.

To each one of these problems, there’s a ready answer that’s tried and tested, and better accepted internationally than what we have at present: proportional representation (PR).

In its purest form, a PR election would have reduced the Liberals and Nationals from 31 seats to 22, rather than 38 to 18.

The arguments commonly levelled against PR are losing force when evaluated against a status quo that’s best suited to a two-party hegemony that no longer exists.

Advocates for single-member electorate systems typically point to their tendency to produce majority government, which is said to be conducive to strong leadership and a clear line of accountability.

However, the first of these has been little in evidence in Australia lately, and the second is, at the very least, complicated by the need for governments to negotiate with powerful, proportionally represented upper houses.

At state level at least, proportional representation in lower houses would render upper chambers elected along the same lines redundant, thereby allowing for their abolition — surely a popular move.

The main obstacle is the entrenchment of the existing system in Australia’s political culture.

The importance of this factor is illustrated by a study of the international history of electoral reform conducted by British political scientist Alan Renwick, which identified only one occasion where a country had moved from a single-member to a proportional representation system, or vice-versa.

Happily, that example is both highly auspicious, and helpfully close at hand.

In 1993, New Zealand voted to junk its old British-style single-member first-past-the-post system in favour of the mixed-member proportional model, and it confirmed the decision by an increased majority at a second referendum held in 2011.

The conservative government that currently rules the roost under this system managed sweeping tax reform in its first term after coming to office in 2008 — including, incredible as it may seem from the Australian perspective, a rise in the goods and services tax from 12.5% to 15%, balanced by cuts in income tax.

It has since been re-elected twice with increased shares of votes and seats, and had only one change of prime minister, after John Key went out top in December.

In the same period, Australia has endured three leadership coups and as many successive electoral disasters for whichever party happened to be in office at the time.

It may perhaps be going too far to put this entirely down to the electoral system. But given the parlous state of public confidence in politics at our own end of the Antipodes, it’s hard to understand why New Zealand’s successful experiment hasn’t stimulated more discussion here.