The occasion of America’s midterm elections last week has stimulated yet another round of discussion as to what ails the nation’s democracy.

The ground was well covered on the weekend by Fairfax’s United States correspondent Nick O’Malley, in an account that encompassed gerrymandering, voter suppression and mounting public apathy.

Overarching these issues is an increasing ideological polarisation among that part of the American public that can still be relied upon to participate in the electoral process.

With remarkable clarity, a study by a non-partisan Washington DC think tank, the Pew Research Centre, shows how those who identify as Democrats and Republicans have increasingly coalesced around distinct sets of liberal and conservative positions respectively across a range of social and economic issues.

This has fed into a vicious cycle in which the parties campaign negatively to rouse the anger of those on their own side of the ideological fence, but in doing so alienate those in the centre. The response of the latter has been to tune out of the entire process — which in turn makes them ever less relevant to the calculations of the campaign strategists.

Writing from an Australian perspective, O’Malley attributes the malaise of American democracy in part to voluntary voting, which certainly stands to reason to the extent that the well has been poisoned by the parties’ imperative to “mobilise the base”.

Does it follow though that our system of compulsory voting has created what Prime Minister Tony Abbott might call a “kinder and gentler polity”? Few who have closely observed our political debate over the past few years would think so.

It might be that ideological polarisation is instead being driven by phenomena common to both countries. An obvious culprit is the changing landscape of the media, both with respect to social media, which ideologues use to wall themselves off from contrary voices (creating what Pew Research describes as “ideological silos”), and the conventional news media, which is certainly becoming more partisan in the United States and is arguably doing so in Australia as well.

Thanks to the Australian National University’s Australian election study series, a regular post-election survey very much like those conducted by the Pew Research Centre, we need not die wondering.

The Pew Research approach to measuring ideological positioning involved identifying ten survey questions on issues generally understood to entail distinct conservative and liberal positions. Reflecting this, I have identified ten questions from the Australian Election Study for which the wording has gone unchanged since 1993, roughly coinciding with the 1994 starting point of the Pew Research study. Five relate to economic issues, the rest to social questions and foreign policy.

As the voluntary voting thesis leads us to expect, Australia shows up negative when the polarisation test is replicated for those who identify as supporters of Labor or the Coalition. The key indicator here is the Cronbach’s alpha measure featured in the Pew Research study, which condenses the tendency of answers to conform to one or another pattern into a single statistic.

In the Pew Research study, this shoots up from 0.50 in 1994 to 0.72 in 2014, with almost the entirety of the shift occurring after 2004. But when applied to the Australian Election Study, a score of 0.54 in 1993 only increases to 0.59 in 2013. While these are respectively the lowest and the highest scores produced across the eight election surveys, the narrowness of the range is quite a bit more striking than any discernible trend from one election to the next.

However, there is one trend that does emerge forcefully from the Australian data, and it’s not one you hear mentioned too often. Put simply, the Australian electorate appears to have moved solidly to the Left.

The chart below, which replicates one from the Pew Research study, shows this trend to be equally evident on both sides of the partisan fence.

As in the US, the attitudes of supporters of the Left-leaning party seem to have become more consistently liberal, in the American understanding of that term. But on economic and social questions alike, the forces that have moved American conservatives further to the Right don’t appear to be exerting much pull in Australia.

On social issues, this shouldn’t come as a surprise — attitudes towards homosexuality in particular have undergone a revolution over the 20-year period in question, and they have been reflected in lesser extent with respect to issues such as abortion and the death penalty.

But it might have been thought that, since the conclusion of the Cold War and its attendant “end of history“, the classically liberal viewpoint has likewise become dominant in economic matters.

Instead, the survey results suggest an electorate with an increasingly social democratic frame of mind. Given a choice between lower tax and maintaining social services, a 56-17 split in favour of lower tax in 1993 was running 36-31 the other way by 2013. Similarly, a 74-13 split in favour of the proposition that higher taxes make people less willing to work had narrowed to 62-17 by 2010, before dropping so far in 2013 (to 49-25) that I don’t entirely trust the result.

Pew Research offers an important note of caution when it observes that an ideological measurement founded on questions that were being asked 20 years ago misses “more recent value divides, such as surveillance and terrorism”. It may be that such issues have been more conducive to conservative opinion.

Perhaps significantly, the only one of the 10 questions identified from the Australian surveys that appeared to indicate a shift to the Right involved foreign policy, with 49% of respondents now rating the Australia, New Zealand, United States Security Treaty as very important compared with 37% in in 1993.

A hardened public attitude towards Australia’s position in international affairs would provide further explanation, if any were needed, for the Abbott government’s motivation in banging the national security drum over the past few months.