Particularly in the last term of minority government, Mr Booth had been allowed to publicly dissent from the official party line, starting by disagreeing with the decision to form an alliance with Labor.

The tactic was good in theory.

He could appeal to the party's base, while the other more pragmatic members maximised the party's involvement in decision-making and broadened their appeal among mainstream voters.

The problem is it didn't translate to votes and the party's support crashed by 8 per cent at the election.

As Associate Professor Kate Crowley put it yesterday. Mr McKim's departure signals a rejection of his co-operative style of politics.

"Whilst it delivered stability for the government, the Greens base haven't seen that delivering Green outcomes," Dr Crowley said.

Under the more radical Mr Booth, the Greens will return to the role of the antagonistic minority on the fringe - with Labor likely to cop just as much of a spray as the Liberal government.

While Mr McKim didn't put up a fight for the job, it's clear handing over the reins to Mr Booth was not his preference.

While he has committed to serving out his term, the demotion will no doubt cause him to think about his future.

The option to move to federal politics has long been flagged for the pragmatist and a spot in the Senate must now be more appealing than ever.