One thing I would worry about if even floating the IDEA of Aussie voting arrangements in this country is that we have so many more people and such widely varied demographics, both cultural and ethnic, that everyone would demand it all be tailored just to suit their personal ideas of 'fairness'.

I suspect you've hit the nail on the head, Bill.

We only got the preferential system in (at first, only in Commonwealth elections) in the 1970s, when there was a campaign for it that seemed to address long-standing disappointment with the inability to shake the dominance of the two major parties; the background is a bit complicated and really of interest only to historians, these days.

On top of that, we have only about 1/15th of the US population, divided into six states instead of 50 (leading to fewer possibilities of state-based fracturing, although several of the larger states might have regions with particular views of themselves) and much less of entrenched "isolationists" (however real or perceived). My impression is that most in the US would describe themselves, if one asked them, as "Americans" first and foremost, and then get into the details of which part of the US they thought they "belonged" to, whereas I suspect many more (as a proportion) Australians might say (depending on context) which state they came from.

Another potential difference, I suspect is that US citizens at a very fundamental level are encouraged to see themselves as the ultimate "individual", with extensions into notions of "community" developing outwards from that central view of themselves. At that same fundamental level I suspect Australians have always had a dialogue between notions of individuality and notion of communality, partly developed historically in the convict era and then encouraged by dealing with the tough vagaries of climate in the bush during development and now celebrated as "mateship" with images of ANZAC and similar evocations.

But I don't see the same politicisation of regions (eg "Texans" vs the rest) except where Western Australians might see themselves as "a bit special and different from" the "easterners"; even then, I don't see it as extreme as in identifying US states as "red" or "blue" states. There are so few of us and we're so far away from the "real" centres of power that we probably stick together more than most northern hemisphere people feel is required of themselves.

Vive la difference!

Cheers, Rowan