Adam wondered how including elections that were contested but lost would change the previous bar graph looking at upper boundaries to re-election. The change is significant. The darker party colour indicates a lost election.

Suddenly Howard and Whitlam jump Hawke in the list. Curtin and Chifley do not come off well either while McMahon lost the only election he contested as party leader.

A larger version of the same chart can be seen here.
Bryan Palmer is trying to construct a thesis of why and how governments lose elections. Another approach might be to look at the maximum a government can achieve in electability when constantly facing the voters to retain their legitimacy.

This is a chart of the number of elections a party leader has won and includes the election they won to come into power. For instance Menzies first election win made him Prime Minister and he then won six as the incumbent giving him a total of seven.

Howard is already on the upper end of what history indicates is achievable in winning elections. Unlike Menzies he does not have a split Labor party to campaign against. Menzies also had a quick run of elections in 1949, 51, 54 and 55. So in a six year period he won four elections which inflates Menzies numbers a bit in this graph, whereas Howard has tended to use the full three year term and in the first six years of his government only contested three elections and after the 2001 win not going up for election until 2004.

We could argue then that Menzies electoral achievements are only a little above what Howard and Hawke have managed. This suggests that there may be an upper barrier in Australian national electoral history that Howard is fast approaching. So rather than looking at the economy, recessions, corruption, etc, there may be a hard barrier in which a party leader ceases to be electable any longer. (more)
Cam Riley: South Sea Republic. Freedom, liberty, equity and an Australian Republic.