In the embarrassment of riches that is the 2010 election season, it is easy to overlook some of the political gems.

The looming race to fill U.S. Rep. Neil Abercrombie’s 1st Congressional District seat could be one of those important political contests that escapes notice.

Abercrombie’s urban Honolulu district runs from Hawaii Kai to Mililani, featuring a good race in both the Democratic primary and general election.

Senate President Colleen Hanabusa is expected to announce this week that she is running for Congress. Former U.S. Rep. Ed Case is already in the race. In the general election the winner will face Republican Charles Djou, also a former legislator now on the Honolulu City Council.

So far U.S. Rep. Mazie Hirono, the liberal Democrat and former state legislator and lieutenant governor, appears to be without a significant challenger for the 2nd Congressional District of rural Oahu and the outer islands.

Hanabusa and Hirono share many political characteristics. Both are women attorneys with a strong labor background; both served in the state Legislature. The difference is that while Hirono led the Consumer Protection Committee and was lieutenant governor, she never really was a legislative leader.

In contrast, Hanabusa since her election to the Senate in 1998 has been in the thick of things, first for assembling a coalition of Democrats that helped reject the nominations of two of Gov. Ben Cayetano’s key Cabinet members, Earl Anzai and Margery Bronster. She presided over several years of controversial nominations to the courts as Judiciary Committee chairwoman and then seize the Senate presidency from long-time legislative veteran Sen. Bobby Bunda three years ago.

In contrast, Case was always the “voice in the wilderness” of the Legislature. Oddly, both Case and Hanabusa both backed Cayetano’s far-reaching government reorganization plans that weakened the power of the public worker unions.

As a legislative leader, however, Hanabusa has been forced to defend the Legislature, from its 36 percent pay raise to its constant fighting with Gov. Linda Lingle. In contrast Case has split from much of the traditional wing of the local Democratic party, tangling with both U.S. Sen. Dan Inouye and trying to oust U.S. Sen. Dan Akaka. Case has tried to groom himself as a “speak truth to power” reformer, but he has also antagonized many Democratic loyalists.

The winner goes on to face Djou, in the only Hawaii congressional district that has put a Republican in Washington. I can’t wait.