A confluence of ideas may seem counterintuitive. Last week’s federal budget is pointing in the same direction as the Overland online debate over the campaign for same sex marriage. They both betray a remarkably broad willingness to assume that leftness has just about run out of uses for the parliamentary movement that labour made.

Abbott might express this in gnomic alliterations: Barcaldine’s Tree of Knowledge is dead, and Balmain now votes Green.

More anodyne commentators can put it prosaically: Labor and much of labour, who have been losing members and activists over many years, are about to lose this year’s federal election against a Liberal Party that more clearly believes in stuff, because they will fail in their campaign to persuade voters to believe that Labor believes in anything much. Labor’s fall into federal opposition will be deep (certainly) and long (probably). It will further reduce the activist base both of the party and of the movement, and will be compounded by the disgrace and imprisonment of corrupt parliamentarians and officials.

I especially sympathise with those still inside the Labor Party who see the crisis in terms like these. John Faulkner is the one most decisively on the record, but others acknowledge it privately, when they are confident News Ltd cannot scoop their honest remarks.

We can anticipate two kinds of response to this crisis from within Labor over the coming months. One is an effort to use the problems of the party as proof that more left-minded Australians should get involved, especially the young, and help to steer it towards stronger critique and more ambitious policy goals. This is the line Kim Carr has foreshadowed he will run in his book, due for publication in August.

This is a line that used to work for Left factions in recruiting new members to the Party. There was always a desperation behind it – since nobody ever believed it was particularly likely to succeed – but the desperation was never so clear as now. And now it seems even more prone to fail than previously.

To accept Carr’s line, you have to believe that Labor would be likely to use the crushing defeat ahead to remake itself as a more genuinely progressive organisation. Every post-defeat remake since Whitlam’s dismissal has moved federal Labor policies further to the Right, so why should anyone believe this time will be different?

In the meantime, who wants to go through the charade of pretending to care about a Labor victory in September this year? It’s not merely that she’s cactus: if Labor is the only realistic hope for Australia’s Left, surely the only realistic hope left for that only-realistic-hope-for-the-left is for Labor to lose so greatly that it needs to reinvent itself through and through.

Let angry electors sack as many of the cynics as possible. Let the authorities punish and gaol a few more for cathartic purposes. Then those who are in it for belief rather than just their own careers might seize half a chance to start again from scratch. And if that all happens in the prescribed sequence, Labor might be ready to earn the support of its putative support base again. Hang in there Kim: you are a good sort, and the apocalypse may just suit you.

The second kind of response will be Chris Bowen’s approach, in a book also promised before the election. This unmissable tome will argue the crisis is not really a crisis, except in the immediately tactical sense.

In Bowen’s view, Labor has had many good years pushing ideas up to one standard deviation left of the mean. The party does not believe it is able to engage Australian voters if it gives way to the indulgence of reflection — so it cannot reform Australian life at all if it tries to reform more than superficially.

This is how we got the ‘foreign aid’ line in the 2013 budget that pays for Australia’s offshore imprisonment of boat people. Thinking back just three years, it is also how we got ‘no carbon tax under a government I lead’.

It is both how Labor lost its Left support in 2001 and how we got the change of government we are about to get in 2013.

You could call this line cynical if it was not so spectacularly ineffective. But the trickiest shortcoming in Bowen’s line is that it does not seem to work any more. Voters of the Left and Right alike are refusing to be corralled by Labor’s insistence that there is no sane alternative.

The Liberal Party announces an industrial relations policy, Labor shouts ‘WorkChoices,’ and nobody believes or even bothers to wonder. Labor promises a referendum on constitutional recognition for local government and very close to nobody cares at all. Labor crafts DisabilityCare, the one truly impressive edifice Gillard’s government can claim as its own, and the Liberal Party manages to position it as bipartisan. You can’t bullshit most people any of the time if they no longer think you’re worth listening to.

It is possible that the so-called centre-left no longer has a future as a movement for the reform of Australian life on a national level, although that seems unlikely. More likely is that post-decimation Labor will endure as a party for corralling the lefty vote, continuing to draw progressive votes and activity away from genuinely progressive campaigns.

Anticipating Abbott’s thumping win ahead, the greatest strategic question for campaigners on Australia’s various lefts is whether to try to make that prediction untrue by rallying sufficient numbers behind Kim Carr’s objectives, or to make it unimportant by building critical mass elsewhere.

Either approach will take a long time and much effort, with every likelihood of failure.