Labor's really taken to this 10-year budget accounting thing, and why not? Bill Shorten has defied recent benchmarks to remain Labor Leader for a whole term, and shown how stability can help policy formation, writes Annabel Crabb.

Bill Shorten continued on his whippersnippering way last night, outlining a nonchalant $71 billion he says he would trim from the federal budget over the next 10 years if elected to office.

Labor's really taken to this 10-year accounting thing. It seems optimistic, given our inability as a nation to hold on to a prime minister longer than a pair of sunglasses, but there you go.

Shorten is an optimistic guy. And this latest bronto-figure is composed of $6 billion Labor would save by limiting the amount of money private vocational education students could borrow from the Government to fund their studies, and $65 billion which is what Shorten estimates the nation will save when he maintains the deficit repair levy on high income earners and gets rid of Malcolm Turnbull's company tax rates - Turnbull having been unwilling to put his own figure on what they're worth over a decade.

The Opposition's beaver-lodge of policies - built from bits of the existing Australian policy landscape that they have gnawed down with their own teeth - grows day by day.

And directing operations is Shorten, in whom barely anybody has been interested for years, but who now must be recognised as a deeply surprising opposition leader.

Most of all, he's unusual because he's still there.

Shorten is the first Labor leader in 15 years to complete a full term at the helm of his party without being whacked. This sounds like a low bar. It isn't.

Kim Beazley - when he lost the 2001 election - was the last person until now to accomplish this unremarkable feat; since then, you've had Simon Crean, who led the party for two years before he was challenged by Beazley and abdicated in favour of Mark Latham, who led the party to the 2004 election but then punched himself to the mat, then Beazley again, who led the party until 2006 when - dispirited - it turned to the indefatigable Kevin Rudd, whom to its great surprise it turned out Australians liked.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 10 minutes 32 seconds 10 m Bill Shorten explains the Opposition's response to the federal budget

Nevertheless Rudd was hoicked out of office by his deputy, Julia Gillard, who was in turn revenge-whacked by Rudd, who was replaced - in a nice piece of cosmic synchronicity - by Shorten, who had played starring roles in both the previous regicides.

So yes: Shorten, whose job carries an expectation of longevity historically undershot only by ladies marrying Henry the Eighth, is already a standout, by virtue simply of being there and still having a pulse.

But there are other reasons.

Shorten takes to this election a bunch of policies that would have frightened his predecessors to death.

Messing about with negative gearing? Latham floated the idea once as shadow treasurer back in 2003, only to be leapt on from a great height by his then leader Simon Crean; the whole thing was dead within 24 hours.

Persisting with putting a price on carbon? Labor's policy here violates one of the great unwritten rules of politics, which is that once your party tries something and is electorally punished for it, you must never try that thing again for generations.

Shorten has - moreover - utterly ignored the broader historical obligation for leaders who take over from defeated prime ministers, which is that they spend a therapeutic few years abjectly apologising for the misdeeds of their predecessors, just as Beazley spent two years apologising for Paul Keating and three Liberal leaders logged countless apologies for Work Choices.

Shorten has spent no time birching himself about carbon pricing; in fact, he's thrown himself right back into it, a decision which has admittedly assumed an added deliciousness since Malcolm Turnbull became Prime Minister ("Of course, advocating climate action is hard, and running a scare campaign against it is easy," deadpanned the Opposition leader last night, in the best line of his speech. "Mr Turnbull should know - you've done both!"), but was already firm policy when Tony Abbott was still in office, and thus cannot be chalked-up to mere political pleasure-seeking.

The most atypical thing is that these policies were developed fairly carefully, over time, and were duly announced without the usual palaver that has accompanied the announcement - by a Labor leader - of a controversial piece of policy, which is to say the immediate hustling of that leader out into the snow.

Why is this?

Is it because of the unusual charm and charisma of Shorten?

In the nicest possible way: No. It isn't.

Shorten, who came into politics encased in the tights and cape and impossible expectations of a political wunderkind, lost his sheen memorably when he orchestrated the putsch against Rudd in 2010 and aged visibly three years later when circumstances obliged him to commit regicide a second time, against Gillard.

By the time he won the leadership, the expectations of him were as low as the spirits of the Labor members who put him there. He lost the popular vote against Anthony Albanese, but won thanks to majority support in the Caucus.

But here's the thing.

When Shorten, in June 2013, leadenly cast his vote to return Rudd to the prime ministership, thus reversing the coup of 2010, he unwittingly - thanks to the random magic of politics - bought his own safety as Opposition leader down the track.

Because the first thing Rudd did, upon his return to the leadership of this party which had defied him, was to march its demoralised parliamentary members off to the Balmain Town Hall and have them adopt new rules making it very difficult to get rid of a serving Labor leader.

Those new rules have served Shorten well. Without them, he would almost certainly have been rolled last year.

But they have also created a fascinating reminder of what a benefit leadership stability (a quality we can barely remember in this country) can be for policy formation.

Shorten can pledge to knock off negative gearing and his party barely raises an eyebrow. Turnbull maintains support for a schools anti-bullying programme which was endorsed by his predecessor and it creates a near-riot.

The departing WA Labor MP, Alannah MacTiernan, in her valedictory speech this week, spelled out the virtue of the new rules both for peace and for policy:

"It has made us focus on policy to capture the public imagination, rather than the constant search for a new messiah," she said.

"And it has contributed to Labor embracing gutsy, meaningful policies that will take this country forward, particularly in climate change industry and taxation reform."

Sometimes, longevity can breed confidence.

It's not something we've had much occasion to observe, of late.

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