Last night’s ABC news led breathlessly with the announcement that numbers were being counted for a leadership challenge next week in the federal ALP. Other reports are more circumspect, but the prospects for change now seem greater than at any time this year.

Why do political parties keep doing this? Why does leadership only become an issue only in the last year before an election, when destabilisation is more likely to be remembered by the voters, when a new leader has insufficient time to get established, and when change almost inevitably just means burning two leaders instead of one?

Kim Beazley hasn’t changed. He remains the same relatively safe, unexciting pair of hands that he was when returned to the leadership two years ago. His prospects of winning next year’s election were slight then, and they still are. Nor was there ever any reason to think he would change: a man in his late 50s who’s been in parliament 25 years can be assumed to be fairly set in his ways.

Kevin Rudd might do better than Beazley, or he might not. We don’t know. But we can be fairly sure of one thing: he would have had a better chance of making an improvement if he’d been given the leadership 12 months ago rather than now.

On ten occasions in the last ten years, state or federal parties have changed leaders less than a year before an election. Only two of them won the subsequent election, and one of those (John Olsen in South Australia) lost most of his party’s majority. Victoria’s Steve Bracks is the only real success. Nearly all the rest went backwards, and most resigned or were dumped shortly afterwards.

The most recent case is Liberal leader Ted Baillieu in Victoria, who at least made up some ground and can be regarded as a relative success. But he only had six months; had he taken over last year, when most observers thought he had the numbers for a challenge, he would have had more time to build some credibility.

It looks as if parties are so consumed by the need to display “unity” that they put off the difficult decisions until it is too late. As Peter Hartcher put it in September, they “do not comprehend the seriousness of their situation.” But disunity doesn’t go away; if not confronted, it will just break out again at a less opportune moment.

Whatever problems might justify knifing Beazley were already obvious 12 months ago. Putting off the decision has left Labor with no good choices.