If Ed Case and Mufi Hannemann face off in the 2012 Democratic primary for the right to succeed retiring U.S. Sen. Daniel Akaka, it’ll be a battle between two guys attempting comebacks from terrible political timing.

The independent-thinking Case was the Democrats’ golden boy in 2002. After narrowly losing his underdog campaign for the party’s nomination for governor against Mazie Hirono, he smashed Matt Matsunaga and Colleen Hanabusa in a special election to succeed the late U.S. Rep. Patsy Mink.

He easily held the seat in 2004 against Mike Gabbard, and if he waited for one of Hawaii’s two octogenarian senators to retire, he seemed the certain front-runner to join the world’s most exclusive club.

But Case didn’t want to wait and surprised everybody by challenging Akaka in the 2006 Democratic primary in what turned out to be a major miscalculation.

Mainstream Democrats led by U.S. Sen. Daniel Inouye were furious at Case for cutting in line, and he lost traction when the election turned into a referendum on the Iraq War and he was on the wrong side.

He tried a comeback last year in the special election to replace Neil Abercrombie in Congress but finished third behind Charles Djou and Hanabusa after being beaten up by both Inouye Democrats and the Republicans. His main hope going forward is that Democrats who once resented him for not waiting his turn will now consider him to have paid his dues after being slapped around for six years.

After Case self-destructed, the mantle of Democratic golden boy passed to Hannemann. He seemed on a path to finish his two terms as Honolulu mayor and then run to succeed Akaka, who would be 88 at the end of his term and was presumed to be planning retirement.

Hannemann would have been tough to beat for the Senate nomination with his rail project likely well under way by 2012, overwhelming support from party power brokers and a fat campaign fund.

But Akaka started making noises about not retiring, and the opening for governor became irresistible to Hannemann’s political ego, which was being stoked by Inouye’s encouragement.

As with Case in 2006, it was a gross miscalculation. Despite a big lead over Abercrombie in campaign funds and endorsements, Hannemann ran a poor campaign that left voters thinking he needed to be taken down a notch. His 22-point loss was the kind of repudiation few politicians recover from.

With other prominent Democrats such as Lt. Gov. Brian Schatz and Congresswomen Hanabusa and Hirono also considered Senate contenders against the likely Republican candidate, former Gov. Linda Lingle, it remains to be seen whether the two former golden boys will even be in the conversation by election time.