Red-hot contest as Greens circle Senate vacancy

Four names are circling a surprise federal spot that has opened up for the SA Greens, watch out for blood letting, Mike Smithson says.

Nov 09, 2026, updated Nov 09, 2026

The SA Greens preselection for a vacant Senate position at the 2028 federal election is turning into a red-hot four-cornered contest.

The capable and formidable Barbara Pocock is stepping down after only one term due to family reasons.

It caught many by surprise as she’d led the Greens’ charge on many federal issues.

Pocock has been no shrinking violet in the national capital and will be missed for her no nonsense and forthright views.

She played a leading role in the parliamentary hearings and public scrutiny following the PwC accounting firm tax scandal in 2023.

So, who will get the nod for a walk-up tilt at a six-year term in the Senate?

State leader Rob Simms has been there before and jumped in to announce his candidacy for preselection stating he was receiving party member calls to do so.

Simms is high profile in SA and speaks with believable authority on most subjects, especially saving trees in the park lands or his rejection of transforming North Adelaide golf course into a mega complex for the now defunct LIV golf.

He knows the pressure of federal politics having briefly been there before after the resignation of sitting SA Senator Penny Wright.

But he was tipped out of office within a year at the 2016 double dissolution federal election.

Some might see his return as a logical step, but others aren’t so sure.

There will be 800 members eligible to vote by November 27, and they have a choice of four candidates, including Simms.

Many observers are now saying young gun Isaac Astill is the one to watch in a race which could go down to the wire.

He was also quick out of the starting blocks and has undoubtedly given the two most fancied combatants a scare.

Astill was a staffer in Senator Pocock’s office and worked alongside Katie McCusker, who’s also on the ballot paper.

She could be forgiven for assuming that she has a legitimate claim on such a juicy career move into the Senate, having given all comers a run for their money in past state and federal elections.

She shone in the Dunstan by-election after Steven Marshall vacated the seat in 2024 where Labor won by a small margin after fierce hand-to-hand combat with the Liberals.

McCusker gained an impressive 5.5 per cent swing to the Greens which helped Labor sneak over the line on preferences.

She was also prominent in the federal seat of Sturt, which also changed hands to Labor, with the Greens holding their own as the red tsunami swept through.

Bev Morris is the fourth person on the Greens preselection ballot paper and isn’t expected to trouble the scorers too much.

She ran in Schubert in this year’s state election, but that was never going to upset Liberal leader Ashton Hurn’s re-election.

From what I’m hearing Astill is firming as favourite for many reasons which are likely to rock the Greens boat all the way to Lake Burley Griffin.

Pocock says she looks forward to one of the four stepping up when the time comes, but says party bylaws prevent her from any public endorsement.

Long-time powerbroker Senator Sarah Hanson-Young is not up for re-election until 2031 and is also prevented from backing favourites.

But something tells me which voting direction they might be heading.

Astill is described as an articulate doer, who’s learnt his political craft in the backrooms and put it to good use in public.

That alignment of prominent party influencers helps him but could leave McCusker and Simms in the dark.

It’s been suggested Simms has largely led his own publicity machine for preselection rather than being hoisted on the shoulders of other party faithful.

Some see him as needing to stay at a state level to keep the party relevant in South Australia.

A move to Canberra could be viewed as convenient for Simms rather than the Greens.

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Simms, himself, remains forever optimistic but knows it’s a genuine contest.

His website preaches three simple words: Hope not hate in relation to the volatile national climate we live in.

“The competitive preselection process of the Greens sets us apart,” he says.

McCusker may feel betrayed and blindsided by an office workmate, who’s now potentially overtaking her in the popularity stakes, and with high-profile backing.

Astill proudly states that it’s time for the Greens to be bold.

“The Greens are at a crossroads,” he says on his website.

“The political landscape is crumbling.

“One Nation has seized the moment and our vote has flatlined.”

That’s a brave assessment from someone who has no real authority to be casting judgement at this stage of his prospective career.

What else do we really know about Isacc Astill?

He was raised in Yankalilla and is now a renter in Adelaide.

He’s been involved in constructing national movements across Australia with a focus on saving the environment.

They include Stop Adani and School Strike 4 Climate protests.

That all sounds pretty much grassroots Greens, added to his national award of Bob Brown Young Environmentalist of the Year.

He might have been a secret weapon the other candidates didn’t see coming, but the contest is never over until the final ballot paper is cast.

The 2028 federal election is likely to be the catalyst for substantial change with Labor and Anthony Albanese supposedly on the nose and the Liberals still fighting for the conservative high ground.

One Nation could remain a potent force but there’s the possibility that will not happen.

The Greens may prove to be the slow plodder with a track record which their older supporter base still trusts.

Electing the right candidate with forceful dynamics is pivotal.

A new SA Greens Senator could join a long list helping contribute to holding the balance of power.

It’s also likely that some blood will be spilled in the Greens camp within a few weeks, when preselection ballots close.

The exact spillage is something we may never know about.

Mike Smithson is also weekend presenter and political analyst for 7NEWS.

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