In their two-decade history as a nationally organised party, perhaps the biggest disappointment the Greens have suffered has been their ongoing failure to poach the state seats that cover their electoral heartland of inner-city Melbourne.

At federal level, this area has delivered what looks to be a secure foothold in the House of Representatives, at least for as long as the seat of Melbourne is defended by Adam Bandt.

The first indication that the Greens might be capable of such a feat was the 2002 state election, when the party outpolled the Liberals in four seats and came within 2% of unseating Bracks government minister Bronwyn Pike in Melbourne. They had good reason to feel confident of going one better in 2006, but intensive efforts by Labor in the last week of the campaign saw Pike and her inner-city neighbours again scrape home. Then in 2010, the Greens gained primary-vote swings that would have been sufficient to win them Melbourne, Richmond and Brunswick, had it not been for the Liberals’ decision to direct preferences against them.

The Greens surely thought the stars had finally aligned in July 2012 when Pike blithely forced Melbourne voters to a by-election by abandoning her seat mid-term. But they again emerged empty-handed after a narrow win by the seat’s present Labor member, Jennifer Kanis, who was presumably aided by a surprisingly weak turnout.

If this accumulation of disappointments has caused them to temper their optimism, they haven’t been letting it show. As the campaign for the November 29 election began, the party published full details of internal polling conducted by Lonergan Research, showing it with a 53%-47% lead in Melbourne and a 54%-46% lead in Richmond.

Spirits would have been further lifted by what look to be extraordinarily strong results in published statewide polling.

The first two polls conducted by Fairfax’s new pollster Ipsos have rated Greens support at 17% and 16%, and two Morgan SMS polls have both had it at 18.5%.

While not everyone has been going that far, the aggregation of polling results featured on my blog The Poll Bludger shows the consensus of the six pollsters to be a Greens vote of 14.2% — fully 3% higher than at the 2010 election.

However, this figure looks questionable if the same aggregation method is applied to all published polling conducted over the last two parliamentary terms, as is charted out in the display below.

It turns out that the Greens vote as measured by the pollsters before the 2010 election was even higher than it is now, with an aggregated result of 14.8% — quite a bit higher than the 11.2% they actually received.

2010 turned out to be something of a high-water mark for the Greens, at least in the short term. Last year’s federal election was the first since 1998 at which they lost ground, and the chart also shows a modest downward trend in their state polling after the 2010 state election.

Then in late 2013 came an apparent reversal of the trend, which has also been evident in federal polling, and which happened to coincide with the election of the Abbott government.

Even so, such was the Greens’ historic strength at the time of the 2010 state election that they will surely have their work cut out improving on it this time around.

Why then might they be tracking for a boost of around 10% in Melbourne and Richmond, as the aforementioned poll results seem to indicate?

One possibility is that the Lonergan polling is simply off the mark, as electorate-level automated phone polls so often proved to be at the federal election — certainly not least those conducted by Lonergan.

On the other hand, we could well be witnessing an ongoing intensification of Greens support in inner-city Melbourne as its youthful demographic grows ever more disconnected from the old paradigm of major party politics.

Adam Bandt gave that notion a boost when he was handsomely re-elected last year, despite the Liberals repeating their preference gambit from the state election.

However, much of that was clearly to do with Bandt personally. If the Greens were able to replicate Bandt’s performance at the state election, they would bolt home in Melbourne and Richmond with margins of around 7% and 6% respectively.

But it’s a different story in the state electorate of Brunswick, which is located within the federal seat of Wills. Despite being the seat the Greens came closest to winning at the 2010 state election, Labor was favoured over the Greens at the federal election by a margin of over 5%.

Tellingly, the Greens’ federal election vote was slightly higher than Labor’s in the state seat of Northcote, which has always been their longest shot out of the four inner-city seats. The distinction here is that Northcote is within the federal seat of Batman, where Labor was handicapped at the federal election by the retirement of a sitting member (even if that sitting member was Martin Ferguson — never much of a favourite of the inner-city Left).

It was in the absence of sitting members that Adam Bandt got his foot in the door in 2010, when former Labor MP Lindsay Tanner retired, and Brunswick replaced Melbourne as the Greens’ strongest seat at the 2010 state election.

No such opening is available to the Greens this time around, with each of the four inner-city seats being defended by Labor incumbents — although the qualification might be added that Jennifer Kanis has had little more than two years to establish herself in Melbourne.

This may be why the betting markets don’t seem to have been moved by the Greens’ polling, with Centrebet offering a return of $2.85 on the Greens winning any lower house seat.