And the Case-Akaka race illustrated the deep divide between the state's establishment class -- in which that seniority is held in high regard -- and a newer generation of politicians.
This cycle, it's likely that a field with several competitive candidates -- including both Case and Hannemann, both more moderate Democrats -- could emerge.
Hannemann released a statement Wednesday saying, "there will be plenty of time to discuss my own personal plan," while Case said he remains "interested in serving Hawai'i in the U. S. Senate."
Democrats are also bullish on Lt. Gov. Brian Schatz and the state's two Democratic Reps., Mazie Hirono and Colleen Hanabusa.
It's also worth noting that the Democrats in this group have often found themselves pitted against one another in elections over the past decade. Case and Hanabusa both competed in a special election for Abercrombie's House seat in 2010, and they split the vote, allowing Republican Charles Djou to win the seat, before Hanabusa put it back in Democratic hands in November. Hirono defeated both Hanabusa and Schatz in a 2006 House primary.
No matter who wins the Democratic nomination, the party should be favored to hold the seat in the general election, though Republicans are bullish on making it competitive if former governor Linda Lingle or Djou runs. But with President Obama at the top of the ticket --- and his home state of Hawaii giving him his largest margin of victory of any state in 2008 -- it will be a tough race for any Republican, no matter their profile.
The GOP is pinning its hopes on Lingle, who has a proven ability to fundraise and high name identification across the state. Lingle said in November she will take six months before deciding on a bid.
Republicans do not expect Lingle's time frame to necessarily change as a result of Akaka's announcement, but they view his retirement as welcome news. If Lingle does not run, former Lt. Gov. Duke Aiona, who impressed many Republicans as the party's nominee in the 2010 gubernatorial race and Djou are the next highest-profile names on the GOP bench.