We saw the Morgan Senate poll yesterday. Like so much else this year, speculation about the Senate election has been guided by “the narrowing”: that mystical force that would drive swinging voters to the Coalition once the campaign focused minds on economic management. It’s now clear to all but a dwindling band of die-hards that this hasn’t happened and isn’t about to.

That means it is necessary to revise the view that the Coalition will be strong enough in the Senate to make life difficult for an incoming Rudd government. The Liberals and Nationals instead find themselves in danger of losing a swag of seats, which opens up a dizzying range of possibilities for the Greens.

A case in point is Kerry Nettle’s bid for re-election in New South Wales. Earlier in the year it seemed safe to assume there would be a traditional three-all split between left and right, with Nettle fighting a probably losing battle with Labor’s number three, Senator Ursula Stephens. In that context, any improvement in the Labor vote would have been damaging for Nettle. Now it seems Labor might be strong enough to win Stephens a seat without excluding Nettle, perhaps even bequeathing her a measurable surplus as preferences. That would boost Nettle’s chances of overtaking and defeating the Coalition’s third candidate, Senator Marise Payne.

The story is similar in Victoria, given that Labor and the Democrats have thought better of repeating their 2004 preference exchanges with Family First (who nonetheless have a vague chance if they can match their vote at the state election).

There has been a further stroke of good fortune for the Greens with the entry of independent Nick Xenophon in South Australia. Such is Xenophon’s popularity that he looks likely not only to win a quota in his own right, but also to deliver the Greens a substantial surplus. This could help their candidate Sarah Hanson-Young overcome the third Labor candidate, Cathy Perry.

Bob Brown should have no trouble winning a seat in Tasmania, the question being how the remaining five seats will divide between Labor and Liberal. There is familiar talk that Brown might do well enough to also carry running mate Andrew Wilkie over the line, but this at least seems a little too optimistic.

The two states where Labor’s strength does not help the Greens are Western Australia and Queensland. Western Australia does not look likely to produce the huge swing required to cost the Liberals a third seat, so a strong hike in the Labor vote has the potential to squeeze out the Greens. Nonetheless, their candidate Scott Ludlam remains the firm favourite.

Labor is also becoming hopeful of winning a third seat in Queensland, which it has never done before at a six-seat half-Senate election. On the other side of the ledger, there is a chance that the Coalition will lose the seat of Nationals Senator Ron Boswell to Family First, who will harness the entire right-of-centre vote if they get ahead of Pauline Hanson. It’s hard to see how Hanson herself could put a quota together, despite all that has been written about her minor successes in preference negotiations.

The remaining wild card is the Australian Capital Territory, where Greens candidate Kerrie Tucker threatens an historic win at the expense of Liberal incumbent Gary Humphries. This would be especially significant because territory Senators’ terms are tied to the House of Representatives, so that an end to the Coalition’s absolute majority would take effect immediately.

While it is likely that not all of these potential Greens wins will come off, they will probably have around five Senators joining the two continuing from the 2004 election, to be joined on the cross benches by Nick Xenophon and continuing Family First Senator Steve Fielding. The Coalition will be reduced from its current majority of 39 seats out of 76 to around 35, while Labor should increase its current 28 seats by four.