THE carbon tax likely peaked as an issue before the price actually started - indeed, its first three months have been an anti-climax.
But Labor will continue to struggle with the political damage it has done since Prime Minister Julia Gillard started dancing with the Greens after the election.
Opposition Leader Tony Abbott, on the other hand, having had the best of times with the debate, faces harder work from now on. He still seeks to keep the tax as centre of his campaigning, a strategy that might need to change in coming months, especially if Labor continues its modest poll recovery.
Abbott also has to explain precisely how a Coalition government would scrap the tax, with all the messy consequences of having, in effect, to ''compensate'' voters for the withdrawal of their present compensation. Those questions will become sharper as the election approaches.
And remember, Abbott is committed to the enormous step of a double dissolution if he can't get the tax repealed - an undertaking that may look rash if voters and businesses seem less concerned about the tax's impact.
The climate issue, which helped Kevin Rudd surf into power in 2007, turned first against him, contributing to his downfall, and then against his successor.
In the Age/Nielsen poll, support for an ''emissions trading scheme'' was consistently high in 2008-09 - about two-thirds of voters favoured one. But then support fell in 2010. The ''carbon tax'' has never had majority backing.
Nielsen pollster John Stirton identifies two ''tipping points'': ''the apparent failure to reach agreement at the Copenhagen climate change conference, which made it easier for opponents of action on climate change to portray Australia as going it alone, and the emissions trading scheme morphing into carbon pricing - the carbon tax.''
After Copenhagen, support for an ETS dropped 10 points to 56 per cent (in February 2010).
Backing for ''a price on carbon'' began at 46 per cent in October 2010 but crashed after becoming closely associated with Gillard's pre-election statement that there would be no carbon tax. It fell to 35 per cent in March 2011, and was 37 per cent in last month's poll.
What's happened, in the broad, over the last few years is that climate change has turned from an emotional rallying cry to a practical policy challenge with all the accompanying difficulties.
Even more important, at the micro level the debate became somewhat less about carbon pricing and somewhat more about ''trust''.
Once the tax started on July 1, things changed again, as people focused on how they personally are affected.
Beforehand, 51 per cent feared they would be worse off, but after a short period of the ''lived experience'' (Gillard's phrase) 38 per cent say they are worse off and a majority, 54 per cent, say the carbon tax is making no difference.
Nationals NSW senator John Williams insists the carbon tax issue is still potent, with higher costs disadvantaging businesses such as a big exporting abattoir at Inverell, and ''more bad medicine to come'' when in 2014 the diesel fuel rebate is reduced.
But West Australian Liberal Mal Washer says: ''We beat the drum too hard on the carbon tax - everyone has stopped listening to the sound of it. The marrow has gone out of it - we need to move on to other issues.''