John Howard started last night’s debate in attack mode, and it wasn’t long before he was focusing on Kevin Rudd’s record: accusing him of having opposed all of the key economic reform measures of the last decade, and contrasting that with the support that Howard claimed to have given to the “sensible” reforms of the Hawke and Keating governments.

The prime minister liked the angle so much that he repeated it a bit later with only slight variations.

Although Rudd basically ignored the attack last night, there are a number of responses he could have made: that what counts as “reform” is often open to interpretation, that some of the present government’s measures have been economically dubious at best, and that Howard’s memory of the 1980s is rather selective (remember the scare campaign against the fringe benefits tax?).

But even leaving those points aside, Howard’s argument is disingenuous because it ignores the way the Australian party system works.

A government’s ability to attract support for its program will always be partly determined by the ideological positions that parties are perceived to start from. Labor will meet less resistance when it embarks on pro-market changes, just as the Fraser government, for example, received broad support for “progressive” measures such as multiculturalism.

The proper comparison to make is not with how the Liberal Party in the 1980s greeted economic reform, but how it reacted to non-economic changes such as a bill of rights, the republic, and native title. Of course, it opposed them tooth and nail. To do otherwise would have been just as surprising as Labor in opposition supporting WorkChoices or the GST.

This working of the left-right dynamic led some observers in 1996 (OK, it was probably just me) to suggest that Howard wouldn’t be so bad for social policy: that just as Keating was better placed on privatisation and deregulation, Howard would be better placed to introduce a republic, because he had less to fear from opposition from the right.

The fate of that little prediction shows the danger of relying on historical inevitability – at least when the right is in power.