It’s fair to say that the voters of Bennelong, having been bombarded solidly for a month, will be relieved to see the back of the byelection circus. Right now, it’s hard to predict who else will be relieved once the votes are counted on Saturday night.

While it’s always wise as a journalist to look through helpful steers on internal polling – given these “insights” are often used shamelessly by campaigns for crude propaganda purposes – the internal consensus on both sides going into Saturday is that the incumbent, John Alexander, most likely, gets there.



Anyone following politics knows political protagonists and the journalists following them can get fixated on things that really don’t matter, but in this case, the collective fixation on Bennelong over the past month reflects the fact that this contest really does matter.

Not many byelections determine whether a government retains its lower house majority, but this one does. If Alexander defies the collective internal prediction, and loses the seat which he retained for the Liberal party at the last federal election, with a margin of just under 10%, Malcolm Turnbull slides into minority government.

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Turnbull can continue to govern in minority, but obviously the degree of difficulty for him increases exponentially, particularly in a government where people routinely struggle to get on the same page, and institutional discipline has been pretty much non-existent.

The prime minister has struggled all year, battling internal divisions, buffeted by events. Turnbull has used Barnaby Joyce’s win in the recent byelection in New England and the successful passage of marriage equality legislation, as well as the government’s bare-knuckle political assault on the Labor senator Sam Dastyari, to try and stabilise his own position and push forward more positively into the new political year.

A Liberal loss on Saturday night would punch a hole in Turnbull’s carefully constructed flotation device. It would not only be back to square one, it would be sub-square one.

So the outcome in Bennelong is critical for Turnbull. As the prime minister would say, this is a penetrating glimpse of the obvious. Perhaps not quite as obvious is that Turnbull won’t be the only political leader having an anxious Saturday.

The best-case scenario for Labor is an upset victory in Bennelong, but in the event the party’s star candidate, Kristina Keneally, falls short, there will be a number of internal and external eyes trained on the size of the swing.

Internally, Labor people are talking about a negative swing of 5% or better as a benchmark – anything less than that will be chalked up as underperformance.

This figure might seem arbitrary but it just reflects history. According to a research paper by the parliamentary library, looking at contests from 1901 to 2014, the average two-party preferred swing against the government of the day at a byelection has been 4%. The ABC’s election analyst Antony Green has also crunched the numbers and his figure is 5% in federal byelections since 1983.

Sticking with history for a moment, both the re-election of Jackie Kelly in the Lindsay byelection of 1996, and Joyce’s recent positive result in New England, suggests contests triggered by MPs having constitutional problems are their own thing, and they can spark a local sympathy vote.

The other dynamic to bear in mind is Labor’s internals have been stirred up ahead of this contest.

Bill Shorten has had to move against Sam Dastyari, who is a figure of influence in the New South Wales right, and Dastyari’s factional fellow travellers, and the prominent leftwing frontbencher, Anthony Albanese, haven’t really bothered to disguise their disappointment with that state of affairs.

Without over-egging the dynamic, and with due acknowledgement that Labor’s internal discipline has been solid in the post Rudd/Gillard period, let’s just observe there are a few noses out of joint in a quarter of the party which prefers to be king, and when it can’t, is more than happy to play kingmaker.

Then there’s nervousness about the polls. While in polling the trend is your friend, and Labor has led decisively all year in all the major opinion polls (the government has lost 72 Guardian Essential polls on the trot), voters are not rating Shorten ahead of Turnbull as their preferred prime minister, and Turnbull’s approval ratings are a jot healthier.

While there are many in the opposition who sense that government is again within spitting distance, not everyone is that confident. Voters are signalling to pollsters week-in and week-out they would throw the Coalition out and elect Labor in any federal contest held today, but do people actually mean it?

Some Labor people think the polls are soft, that the strong performance on the two-party preferred measure post-election isn’t a guarantee that disillusionment against Turnbull translates into a vote for Labor when it matters – on election day.

So if that’s the default question being asked – can we believe this trend, are we really within striking distance of government? – politicians and backroom types will look to any concrete field evidence they can get, and Bennelong is a valid bit of field evidence.

Now, I reckon most readers will already know the stakes on Saturday night are very high for Turnbull, and many will know that Shorten will be judged too, but how many of you have thought about Cory Bernardi?

Bernardi may not be top-of-mind, but he’s another political leader with a bit on the line in this particular byelection. The outspoken South Australian opened the political year with his defection from the Liberal party, and since then he’s bolted together his Australian Conservatives insurgency.

The public polls suggest Australian Conservatives are doing reasonably well in Bennelong for a fledgling political movement. Logic suggests Bernardi’s party would pick up some disaffected conservative votes in this contest, given the Liberal party in NSW has been in an open state of warfare, with conservatives facing off against moderates.

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So a couple of interesting things to consider on Saturday night – does the vote on the right in Bennelong split, and to what degree? Also, what happens with preferences? Are they what the backroom types like to call “sticky” (which means they flow back in large part to the Liberal party) or do they, like One Nation’s preferences sometimes do, go in unpredictable directions?

If Bernardi’s candidate performs well, and the preferences largely flow back, pumping Alexander’s tyres in the event the contest is tight, what then does that presage for new year realignments on the political right?

Bernardi wants to position his party as the “safe” protest vote on the political right in contrast to One Nation, which has been characterised by the Liberal National party after the Queensland election as the “chaotic” protest vote, which helped to return a Labor government in the state.

While a recent quality data analysis of the Queensland election shows that One Nation voters gave most of their preferences to the LNP in 37 of the 38 seats where the result came down to “a shootout” between the LNP and Labor – facts which debunk the post-election official “history” – Bernardi will continue his efforts to style his party as the home of “safe” disaffection.

A solid micro-party result in Bennelong, which flows back strongly in the direction of the Liberals, will help with that styling objective and, in practical terms, it will also make Bernardi’s party harder for the Coalition to freeze out and ignore, with a fascinating state contest looming in South Australia next March.