The former congressman last year lost the Democratic primary for a Senate seat to incumbent Sen. Daniel K. Akaka. In November, voters elected former Lt. Gov. Mazie Hirono to take over the U.S. House seat vacated by Case.

The following is an excerpt from a newsletter titled "Mahalo For The Past; On With The Future" that Case today sent to supporters:

"Yesterday marked the end of my term as Hawai'i's U.S. Congressman. My service, which began on November 30, 2002, came in difficult times, yet I leave Congress with faith in our system and hope for our future. ... It also marked the end of twelve years in office, dating back to my election to the Hawai'i State Legislature in November 1994. These have been the most challenging and rewarding years of my life, especially the last five, during which I not only served over four years in Congress, but campaigned statewide for state and federal office. ...

As to my own future, today I began work with the Bays Deaver Lung Rose Baba law firm in Honolulu. I feel fortunate to return to our private sector, where I worked for two decades before Congress. ...

These past months have also allowed me to reflect on whether I want to consider further elective public service and whether there will be reasonable opportunities to seek office again. The answer has been yes, although I will let the what and when come in its own time.

It is clear, however, that we still face the same challenge of optimum transition in Hawai'i's Congressional representation of which I spoke in the Senate campaign. I am filing the necessary paperwork (technically, Case for Senate 2012) which will allow me to carry over a small campaign surplus and maintain a campaign presence at the federal level. I also will be participating in ongoing public discourse over the multitude of issues we all face.