A chastened Labor Party has taken the first bold step towards an uncertain future, embracing a process that could reveal a very awkward result.
The risk is that the next leader of the party is not the preferred candidate of the MPs he will lead, and that this becomes a recipe for instability.
It is all the greater because, as things stand, the MPs will vote without knowing the result of the ballot of some 40,000 party members that will be completed before they make their choice between Bill Shorten and Anthony Albanese.
The risk is mitigated by the lesson learnt the hard way - that any repeat of the divisions that characterised the last two terms of Parliament will be punished severely, very severely.
The truth is that the new leader will have a mandate no previous Labor leader has enjoyed, having been elected by both the parliamentary party and the membership.
While Shorten is of the right and Albanese is of the left, the pitches of the two men are almost identical - that they each possess the policy credentials, communication ability and negotiating skill to do the job and reach out.
Both volunteer that the other would do the job well if elected, and that they would be honoured to serve under him in the event that they do not win. Both insist the legacy of the defeated government must be defended. Both will resist Tony Abbott's plan to end carbon pricing. Both have played the game hard and carry the baggage of factional fights.
The one big difference goes to the question of ambition. As Albanese noted when declaring his hand, until Friday no one in his 17 years in politics would have heard him express the ambition to be prime minister.
Shorten, in contrast, has worn his ambition like a birth mark, as have most successful leaders.
Another difference goes to style. Albanese, brought up by a single mother on a disability pension, is the better parliamentary performer, who gets enormous satisfaction from ''fighting Tories''. If the test is taking the fight up to Tony Abbott, he has the edge.
Shorten, educated at Xavier College, has a more measured manner and he is just as comfortable addressing company boards as union rallies. An architect of the disability insurance scheme, he has the edge if the task is winning over the middle ground.
Both, of course, are up against a century of history that says no leader installed after a defeat goes on to become prime minister. Both are convinced that Labor can be competitive next time if it gets its act together and harnesses the talent it has in the Parliament.