No one knows whether Kevin Rudd's positive impact on Labor's vote will last. While the potential bounce was long predicted by the opinion polls they could never tell us why. But then again he has always been an enigma. His immediate record of popularity after becoming Opposition Leader in 2006 was equally astounding.
As the Rudd-Tony Abbott contest begins afresh there is a lot more that we need to know. Trying to explain Julia Gillard's unpopularity is the best place to start.
There are various questions. Why was Gillard so unpopular? Why is Rudd now much more popular than she was? Why is Rudd now much more popular than Abbott?
The polls as published in the media don't attempt to answer these questions. They just leave them to journalists and columnists who write accompanying stories based on their own hunches.
There are, of course, many potential answers to the popularity questions. But the fact that there are so many is a complicating factor rather any sort of a resolution.
Take the question of why Gillard was so unpopular, which is crucial because it still remains central to the Rudd-Abbott contest. There are so many possible answers that no single one will do.
She was never forgiven for the method by which she came to office so she lacked the legitimacy and authority that normally comes with the position.
She was never forgiven for breaking her promise not to introduce a carbon tax. Her post-election agreement with the Greens to do so meant that she wasn't trusted and was even seen as dishonest.
She was an unmarried, childless woman and that counted against her with some voters, especially some men.
She presided over perceived failures in policy, including refugees and asylum seekers, the carbon tax and the mining tax.
She presided over perceived failures of implementation, including the GFC school building program. In addition she presided over drawn out and costly programs such as the national broadband network.
She was a poor public communicator and failed to effectively sell Labor's successes, including the economy and foreign policy. In addition she was surrounded by ministers who were also poor communicators and who thus couldn't compensate for her weaknesses.
She alienated the Left in the community by not being progressive enough on issues like gay marriage and asylum seekers and also alienated the Centre and the Right on issues like asylum seekers and taxes.
She presided over a hung parliament and led a minority government.
She was