Parliamentary divergence – the path to political dysfunction

The Senate has always constituted something of a challenge to Federal governments wanting to implement their legislative programmes.  However, that is how it should be, surely – the Senate is supposed to operate as a house of review.  Furthermore, section 57 of the Australian Constitution specifically contemplates the possibility of a legislative impasse and provides a mechanism to resolve it.  The most recent Federal election, a so-called ‘double dissolution election’, is an example of that provision in operation.

But what if the political composition of each of the two houses of Parliament diverged so far that legislative impasse became commonplace rather than exceptional?  At some point, legislative paralysis and political dysfunction would prevail.  Either that or the major parties would have to completely overhaul the way they operate in government.

Several factors contribute to differences in the political makeup of the House of Representatives and the Senate, including the timing of elections and the nature of the ‘electorates’.  The focus here is on the differences generated by the House of Representatives having a form of majoritarian voting system and the Senate having a proportional voting system.

The starting point in this analysis is to compare the combined percentage of first preference votes for the ALP and the Coalition (being the only two potential candidates to form government) in Senate elections since 1983 with the equivalent percentage in House of Representative elections over the same timeframe.  First preference votes are utilised for this analysis (using data from the Australian Electoral Commission and the Parliament of Australia) on the basis that they best reflect electoral support.


Three points stand out.  First, the last three decades have witnessed a significant decline in the level of combined first preference support for the major parties in elections for both the Senate and the House of Representatives.  Secondly, the changes from election to election have been broadly the same in both houses.  Thirdly, the decline in support for the major parties has accelerated since the 2007 election.  In increasing numbers voters are giving their primary electoral endorsement in both houses to independents and minor parties.

The implications of these trends for the composition of the two houses vary markedly, as shown in the next two graphs.  The first addresses the position in the House of Representatives.


Even as their share of the primary vote has slipped inexorably towards 75%, the major parties have retained 97% of the seats in the House of Representatives.  In other words, a significant reduction in electoral support has had little impact on their domination of this chamber.  That domination is underwritten by the chamber’s majority-preferential single member district voting system.

The picture in the Senate is very different.

senate diverge 3.png

The proportion of seats won by the major parties in the Senate correlates much more closely with their share of first preference votes.  Accordingly, as the latter has declined over time, so too has the former.  This reflects the proportional voting system utilised for the lower house.  (The correlation is not perfect due to the complexity of that voting system and the disproportionality of the allocation of Senate seats among the states and territories.)

The previous two graphs demonstrate that the declining primary support for the major parties in both houses manifests itself in the composition of the Senate but not in the composition of the House of Representatives.  The result is increasing political divergence between the two houses, as shown below.


The difference in the voting systems of the two houses has had a particularly significant impact over the last four elections as the support for independents and minor parties has risen.  An appreciable gap has opened up between the major parties’ dominance in the House of Representatives and their position in the Senate.  In the latest election, they won 97% of the seats in the former but only 74% of the seats in the latter.  This disparity is reflected in the size of the crossbench with which the current government must deal in order to gets its bills through the Senate.

It is difficult to foretell whether the trend away from the major parties will continue.  However, the rise of both populism and protest voting in similar jurisdictions suggests that it could.  Events like the Trump nomination, the Austrian presidential election, the Berlin state election, and Brexit point to increasing voter unpredictability and volatility.  More often than not, it is existing major parties that suffer.

If the major parties in Australian Federal politics continue to lose support to independents and minor parties, their Senate ‘shortfall’ will continue to rise.  The need to negotiate with a growing number of Senate crossbenchers will likely further constrain the ability of each of the major parties to legislate when in government.  The resulting government inaction might in turn lead to additional voter frustration with the perceived political establishment, to further desertion from the major parties, and to an even greater divergence in the Senate.  It is hard to imagine, but perhaps one day a future government will look back longingly at the 2016 Senate crossbench.

Ross Stitt is a PhD Candidate from the University of Sydney