If you wanna talk aussie politics there's no better or worse place to do it than aus/pol/ on 4chan's politically incorrect board. There's usually a thread up from 9am until 1am every day though you might have some difficulty finding it without being on a PC and pressing F3 to directly search for aus/pol/ on the catalogue.
"/pol/ - Politically Incorrect" is 4chan's board for discussing and debating politics and current events.
boards.4chan.org
Be warned there's far too much shit posting, autism and general mental illness on display there at all times, it is after all 4chan, but it is still the best place to talk about politics.
As for which political groups wants to legalise it, fuck them all. At best they're ignorant of what they're really asking for thinking a step in the door will let them eventually fully open it bringing freedom to us and the plant which won't happen or at worst they know exactly what will happen if it's legalised being that it's legal for some while the war continues against us and don't give a fuck. Worse still if you single cause vote for hardcore lefty cunts like the greens and somehow they get in power you're not very likely to see them actually legalise anything but instead act on their other economic and cultural policies first which will ruin the nation and force the pendulum to swing so far back to the right it'll be another century before the debate about making it legal even comes up again.
Personally I think our best hope is the United Australia Party this election because they don't yet have a drug policy but have a massive following due to their desire to end all the covid bullshit, end the national debt, save the economy from insane government spending, etc. and given they're mostly about jobs and the economy it shouldn't be a hard sell to point at places like the USA and Canada and say such a system where the people get to compete against each other to legally grow and sell cannabis will result in record job creation and a massive boost to the economy and the savings that will be made from not arresting growers or users ever again will free up vast amounts of police resources which will make our communities safer. They're a new party that actually stands a chance of wrecking the two major's dominance so if we can get them to form a drug policy we like early on they might actually push their luck when they run out of the larger things to deal with. If we don't hound them though about the best we can hope for are minor parties like One Nation standing up and saying the black market tier prices medicinal users currently pay is insane but even they won't push for legal home growing to change things and they certainly don't give a shit about recreational use at all.