Coalition likely to face difficult Senate

On current Senate results, the Coalition can expect to win 32 of 76 seats at most, which would be a one seat loss from the pre-election Senate. Although 32 Coalition seats are possible, the most likely outcome is 30 Coalition, 27 Labor, 9 Greens and 10 Others. The Coalition would then need 9 of the 10 Others to pass legislation opposed by Labor and the Greens (a tied vote in the Senate is lost).

All states now have at least 87% of enrolled voters counted. Even though voting is compulsory in Australia, some people do not vote, so final turnout will be about 92-95% for each state.

In the new Senate system, voters number at least six boxes above the line, or 12 below the line, though a single "1" above the line will still be counted as formal. Currently we only know primary votes, with preferences data entered into a computer system for each state and territory. The new Senate system is unique in Australia, and there may be surprises when "The Button" is pressed to allocate preferences and determine the Senate winners.

Assumptions being made by analysts are that micro party preferences will scatter, and that the major parties and Greens, being well known, will benefit more than other micro parties. Micro parties that are ideologically similar, such as the various Christian parties, should have a tighter preference flow. When distributed, major party preferences are more likely to follow the How to Vote card.

I had thought that 0.5 a quota on primary votes would give parties a decent chance, but the fragmentation of the Others vote has meant that only 0.3 quotas has been required in most states.

The following table shows the Senate seats that the ABC considers won or likely. I will then give the quotas of the major contenders in all states, and comment on who is most likely to win. Others are Pauline Hanson, Jacqui Lambie and Derryn Hinch.

NSW: Coalition 4.71 quotas, Labor 4.07, Greens 0.94, One Nation 0.53, Liberal Democrats 0.39, Christian Democrats 0.34, Shooters 0.26. Even though One Nation does not do well on preferences, I think their lead is too great. Either the Liberal Democrats or Christian Democrats should win the final seat.

Victoria: Coalition 4.39 quotas, Labor 4.01, Greens 1.36, Derryn Hinch 0.78, One Nation 0.24, Animal Justice 0.22. I expect both the Coalition and the Greens to comfortably win the final two seats by attracting more preferences than One Nation and the micro parties beneath them.

Queensland: Coalition 4.62 quotas, Labor 3.46, One Nation 1.18, Greens 0.87, Liberal Democrats 0.37, Nick Xenophon Team (NXT) 0.26, Family First 0.25, Katter 0.24. Labor will easily win one of the doubtful seats, and the Liberal Democrats have a clear lead for the last seat. Unless the NXT, or one of the other micro parties, can win more preferences than expected, the Liberal Democrats will win the last seat.

WA: Liberals 5.04 quotas, Labor 3.67, Greens 1.35, One Nation 0.52, Nationals 0.33, NXT 0.28. It is possible that both the Nationals and Greens could pass One Nation from preferences, but it is more likely that one of the Greens or Nationals miss out. I favour the Greens to defeat the Nationals as they should improve their position further on very late counting, and will gain preferences from other left micros.

SA: Liberals 4.31 quotas, Labor 3.55, NXT 2.81, Greens 0.73, One Nation 0.39, Family First 0.36. There is a slight chance that Labor could lose the final seat on Liberal preferences, which go to Family First. However, the flow of Liberal preferences would need to be massive, and I do not think this will happen.

Tasmania: Labor 4.38 quotas, Liberals 4.23, Greens 1.43, Jacqui Lambie 1.07, One Nation 0.34. After being demoted to No. 6 and No. 5 on the Labor and Liberal tickets respectively, Lisa Singh and Richard Colbeck have won many below the line votes. There is a three-way contest for the final two seats between Labor, the Greens and the Liberals, and it currently looks as if Colbeck will miss out, while Singh will be elected from No. 6 on the Labor ticket.

Here is my likely Senate table. I have added a column for One Nation, and a Liberal Democrat win in Queensland is likely. I have kept the final seats in NSW and WA undecided, with NSW between the Liberal Democrats and Christian Democrats, and WA between the Greens and Nationals.

Senate system not to blame for One Nation success

In 1998 and 2001, when One Nation last rose, the vast majority of votes for parties other than One Nation went to the Coalition, Labor, the Greens and the Australian Democrats. It would have been damaging for any of these parties to do preference deals with One Nation, so that party was put last on all mainstream group voting tickets.

At the last two Senate elections, there has been a massive surge in the Others Senate vote. As many Others are micro parties, they are much more likely to deal with One Nation, especially if they thought they could benefit from One Nation preferences. The party base of a micro party is not large enough to worry about controversies from dealing with One Nation.

Kevin Bonham has simulated the NSW 2013 Senate election under the old group voting ticket system, assuming there had been a double dissolution. He finds that Hanson would probably have won from just 1.2% of the primary vote.

Hanson herself would have very likely won even if a normal half-Senate election had been held. However, One Nation's likely wins in NSW and WA would not have eventuated had a half-Senate quota been used. The double dissolution reduced the quota from 14.3% to 7.7%, and this helped One Nation.

Labor provisionally wins Herbert by 8 votes

With all votes counted, Labor leads in the Queensland seat of Herbert by just 8 votes out of almost 90,000 formal votes. A recount will start tomorrow, and is expected to take two weeks. The result following the recount could be challenged in court, but the winner will be seated until the courts decide.

If Labor holds on in Herbert, the Coalition will have a bare majority of 76 of 150 House seats, with Labor on 69 and 5 crossbenchers. After appointing the Speaker, the Coalition would have 75 of 149 votes on the floor, and Turnbull could be exposed to possible defections from the hard right.

Adrian Beaumont, PhD Student, School of Mathematics and Statistics, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.