History is against Julie Bishop becoming prime minister because in Australia good foreign minsters don't get the top job.
Since the start of the Menzies era only two foreign ministers - or external affairs minister, as the post was called until 1971 - have become PM.
They are the largely unlamented Billy McMahon and, in between his two stints as PM, Kevin Rudd.
Gough Whitlam combined the two for a time.
Yet Australia has had plenty of highly competent foreign ministers who never made it to The Lodge - Percy Spender, Richard Casey, Garfield Barwick, Paul Hasluck, Andrew Peacock, Bill Hayden, Gareth Evans and Alexander Downer.
However, Ms Bishop has already achieved one milestone - being Australia's first female foreign minister.
