A former banker will campaign against the unions and a former unionist will campaign against the banks. There's an uncanny symmetry to Election 2016 right down to the perfectly balanced polls. Annabel Crabb writes.

It's on. The poor old Australian electorate, subjected to unspeakable switcheroos and short-sheetings these last nine years, will - thanks to the Senate's rejection of the ABCC bills last night - be forced back to the ballot box on July 2.

Malcolm Turnbull, a former banker, will spend the next 75 days campaigning for a higher degree of accountability for unions.

Bill Shorten, a former unionist, will spend the next 75 days campaigning for a higher degree of accountability for banks.

Neither of them has ever done this before; led a federal election campaign, that is.

And each of their political parties has - in the past six years - knocked off one leader to be replaced by another who was in turn knocked off by the first guy again.

These elements impart a certain uncanny symmetry to the whole contest, enhanced by the metronomic insistence with which the published polls returned this week to a scrupulously-balanced 50/50.

No-one in their right mind thinks 75 days is a reasonable length of time for an election campaign. And yet, this is the price Malcolm Turnbull has elected to pay for the privilege of fighting an election campaign around something on which he and his whole party agree - the wickedness of the Construction Mining Forestry Energy Union - rather than the undulating and scenic range of issues on which Malcolm Turnbull's views drive some other people in his party absolutely crazy.

The rest of the campaign platform is a deliciously blank slate for the Government. All they really have for sure so far is that there needs to be a really big and arresting idea, that doesn't cost anything or scare the bejesus out of anyone, and that they really must ensure that all bold plans are outlined before the election rather than after so as to avoid the horrible fates of former promise-breaking governments.

Labor, on the other hand, has rolled out a bunch of policies that conventional wisdom would immediately identify as surefire vote losers: A tax increase on ciggies! A kick in the goolies to negative gearing! The return of carbon pricing!

Which rather invites the question: How is it that Bill Shorten, a not especially popular leader, can preside over such policies and not yet have been pecked to death from within, yet Malcolm Turnbull – specifically selected by many as the Coalition's actual messiah – cannot even benignly preside over a schools' anti-bullying program introduced by someone else entirely without estranging some rump or other?

Political campaigns, in the end, come down to discipline. The extent to which a smaller group of highly-informed people is prepared, uncomplainingly, to endorse a certain course of action will go a long way toward informing the responses of the broader electorate.

And discipline is one area in which this contest starts out asymmetrically.

Annabel Crabb writes for The Drum and is the presenter of Kitchen Cabinet. She tweets at @annabelcrabb.