“The ALP is heading for its biggest defeat ever under Gillard,” I was told recently.

The confident assertion promptly fell to pieces when I asked for a definition of “biggest defeat ever”. A garbled account of seats, votes and swings followed. Such are casual political conversations. Few people know the figures.

But the question is a good one. How do you measure the extent of an election defeat? If the Gillard government is annihilated this year, what measures of comparison should we use?

Here’s a table showing ALP statistics for three different measures: the proportion of seats won in the House of Representatives, the two-party-preferred vote, and the primary vote. The ALP’s winning election years are shaded yellow.

The table includes every election since Federation, except for the first three: 1901, 1903 and 1906. These have been excluded since they took place before the formation of the two-party system as we know it. Since 1910, elections have been fought between the ALP and the non-Labor parties under a variety of names.

The ALP has won 14 of the 40 elections held since 1910. I have categorised the 26 elections it has lost into four groups:

1. Seven major defeats where the ALP won no more than a third of the seats in the House: 1917, 1925, 1931, 1966, 1975, 1977 and 1996.
2. Seven significant defeats where the ALP won between 33% and 40% of the seats: 1919, 1922, 1934, 1937, 1949, 1955 and 1958.
3. Nine moderate defeats where the ALP won between 40% and 50% of the seats: 1928, 1951, 1954, 1963, 1969, 1980, 1998, 2001 and 2004.
4. Three near misses where the ALP just fell short: 1913, 1940 and 1961.

By any measure, the ALP’s most successful election was John Curtin’s victory in 1943. Curtin won 66.21% of seats in the House. James Scullin won 61.33% in 1929 and Bob Hawke won 60% in 1983.

Curtin’s victory is also the only election in which the ALP polled in excess of 55% of the national two-party-preferred vote. [Note: Early figures for the two-party vote are not shown either because there are no precise figures available or because the election took place before preferential voting was introduced in 1918. Up until 1955, two-party figures contain a small element of estimation because some seats returned a member unopposed.] [Read more...]