The Greens have broken through. They are a potent force that will have a casting vote on contested legislation until 2017 at the earliest. They have won their second ever Reps seat and may yet win a third, and will have nine senators. It is a result that only the party’s greatest optimists hoped for. Far from wilting during the campaign, the Greens vote solidified. Come polling day, they walked the walk electorally.

The most important question for the Greens now is how much of yesterday’s 3.6% swing in the House of Reps and 3.9% swing in the Senate was driven by disillusionment with Labor, and how much was genuine attraction to the Greens, and therefore more likely to be long-lasting.

The consensus is likely to be that it is primarily disaffected Labor voters. But they’re now Green voters, and they may like it.

It’s a slightly academic question in the Senate, because the Greens are likely to have the balance of power there for six years, such is the strength of their performance yesterday.

But in resolving that question lies the key to just how far the Greens can go in creating a genuine third force in federal politics. The breakthrough win by Adam Bandt shows Labor has much to be fearful of in inner-city electorates. Labor now has a real problem with its reflexive strategy of veering to the Right on key issues, confident preferential voting will deliver the votes of disaffected supporters back to it. That may now cost it seats, even if it assumes it can rely on the Adam Bandts of the world to never back a Coalition government.

But the Greens are also working hard to develop a regional presence. The Greens’ second-biggest Senate swing, 5.5%, and biggest Reps swing, 5.15%, was in Queensland. Rachel Siewert and Christine Milne have been working hard on rural issues. On a number of issues like food security and coal mining in agricultural areas, the Greens have strong appeal to rural communities. Only on water is there still an ideological divide, although the complexities of water mean the Greens have common cause with some in the MDB.

There are some challenges for the Greens. A bigger party room — it will double in size after July 1 — is likely to lead to more divisions, especially once they take over as the balance of power party in the Senate.

And the Greens will now face the full fury of the mainstream media. They are no longer a distraction, playing with the fairies at the bottom of the garden. They are now a clear and present danger to the status quo. Expect News Limited to commence an aggressive campaign against the Greens, every bit as dishonest as the one it waged against the ALP when in government. Expect the business media to talk endlessly of ‘sovereign risk’ and the threat to jobs and investment posed by the Greens (and by the balance of power independents in the Reps).

It will be ugly, but the Greens expect no less. They’re taking on the major parties and politics-as-usual and, for the time being, momentum is with them.