Split-ticket voting

Split-ticket voting refers to when a voter in an election votes for candidates from different political parties when multiple offices are being decided by a single election, as opposed to straight-ticket voting, where a voter chooses candidates from the same political party for every office up for election.

In Australia, federal elections in recent times have usually involved a House of Representatives election and a half-Senate election occurring on the same day. Most states, with the exception of Queensland and Tasmania, also hold elections for both houses of parliament simultaneously. An example of split-ticket voting in Australia is a voter who gives their first preference to the Liberal Party on the House of Representatives ballot paper and to the Family First party in the Senate.

In the 2013 election, the Senate vote for both the Liberal and Labor parties was considerably lower than their lower house vote, demonstrating that a large number of people voted for a major party in the House of Representatives and a minor party or micro-party in the Senate. There are many reasons why a voter may do this, including the fact that many parties only stand candidates for the Senate (leaving their supporters unable to vote for them on their lower house ballot), the much lower quota required for election to the Senate compared to the House of Representatives (14.3% versus 50%), and a desire to check the power of the government by preventing it from controlling the Senate.

From 1978 to 2008, when the Australian Democrats held representation in the Senate, the Democrats benefited greatly from split-ticket voting, as their Senate vote was always much higher than their House of Representatives vote. The party built its campaigns around "keeping the bastards honest", a reference to holding the balance of power in the Senate so as to prevent the chamber from becoming either a rubber stamp for the government or a tool of obstruction for the opposition.

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