> I can't comment on instant runoff voting, but my impression from following politics in Europe is that proportional representation creates a situation where all legislators toe the party line, as opposed to still having some degree of independence, as in Britain or the US. This gives an undue amount of influence to a small number of party bigwigs, and the inevitable mess results.

You know, if you'd said that fifty years ago, I think you'd be right. But have you paid much attention to US politics over the last ten years? The Republicans have engaged in strong campaign against "Republicans In Name Only", and have enjoyed enormous party discipline as a result, even when it seems like they shouldn't.

I suspect the future of congressional politics in America looks like European-style parties only with no European-style party diversity.