The state of the minor party vote often gets ignored these days with commentary focusing on the large ALP and not so large Coalition primary votes. Yet, the decline of the minor party vote since the 2004 election makes has some pretty profound consequences for the final two-party preferred result at the coming election.

If we track both the minor party primary vote and the minor party primary vote swing since the 2004 election, the minors have experienced quite dramatic movements over the period.  

In the middle of 2005, the minors vote increased by 25% – no mean feat. Yet most of that growth came at the expense of the Coalition primary. Slowly over the period of 2006 the peak proved unsustainable and then Rudd came alone and decimated the minors.

If we look to the primary vote swings of the Coalition, the ALP and the minors together, it gives us a good idea of how the composition of the vote of each party was changing, and where voters were not only moving from, but moving to.  

There’s quite a lot of info in that graph if you start comparing political events with the subsequent change in the primary vote numbers. It’s worth at least ten minutes of fun if you’re a bit nerdy. What stands out particularly is that the post 2005 budget period really eroded the Coalition primary vote, and (with the benefit of hindsight) the parked voter theory came into play. It appears that ex-Coalition voters really did park their primary vote with the minor parties during the 2005/06 financial year.

Yet when Rudd came along, that phenomenon ended abruptly. Minor party voters moved en masse to the ALP corner and their primary vote was boosted to the high 40s and occasionally the low 50s.

With that 5% group of ex-Coalition voters that moved to the minors in 2005, it makes you wonder whether that increases the difficulty of the Coalition gaining them back during the campaign. These folks haven’t just changed their voting intention once over the period, but twice. They first moved their primary away from the Coalition and then moved it again to the ALP under Rudd. For the Coalition to get this group back, it has to convince them that their last two voting intention changes were erroneous. A tough ask by any measure.

There are also two big questions that pop up with the minor party vote decline; will the preference distributions be unusual this year as a result of the minor party vote being relatively low, and secondly, is the minor party vote level actually this low or are the minor party voters having difficulty being sampled properly by the pollsters?