I reckon preferential voting is hugely significant too. Less religious influence certainly helps, and what remains of Christianity here is mostly traditional, as in Anglican and Catholic, as opposed to America's cultural Frankenstein - Pentecostalism (although see Scummo).
But yeah, Australians aren't great at history it seems - frontier wars anyone? If we can't do history in our own backyards, we certainly can't apply it to movements in other cultures and places. History is substituted for mythology in fascist world views, so when a populace lives on the myths of colonisation it's easy to adopt other mythological narratives, i guess?
