THE Commonwealth Electoral Act was comprehensively rewritten in 1918 to introduce preferential voting, replacing the previous “first past the post” system that had existed in the years after Federation. The change was in response to the rise of the Country Party in the aftermath of the First World War – a third major party – and the prospect of the loss of seats to Labor through a split in the non-Labor vote. The three-party system which preferential voting helped to support has remained fundamentally unchanged to this day. The system has also encouraged the participation in elections of minor candidates…