2010 was the Green's high-water mark, and it was a large protest vote, everything was suggesting that this was NEVER going to be a good election for them, on paper.
Having said that getting Bandt to 43% primary is ASTOUNDING - but their national vote is slightly above their result from 2007. Palmer, as mentioned, was the recipient of the protest vote this year, but he drew from both sides (although from the ALP more, but it varied).
something that I've noticed both from 2010 in the UK and from this board in general, is that Green parties in countries that use fptp (or av/irv in this case) are good at targetting and getting people (re)elected despite a bad swing in general
