Rep. Neil Abercrombie’s (D-Hawaii) imminent departure from Congress could pose another election problem for House Democrats, who have had three longtime Members in competitive districts announce their retirements in as many weeks.Under Hawaii law the special election that will be created by Abercrombie’s resignation is a winner-take-all contest, which all but guarantees that it will be both competitive and expensive and gives Republicans a pickup opportunity.If both former Rep. Ed Case and state Senate President Colleen Hanabusa decide to run in the special election, the two well-known Democrats could split the vote and position Honolulu City Councilman Charles Djou (R) to win the contest. At the end of September, Djou reported having $268,000 in the bank — more than twice as much as Case. At that point, Hanabusa was not yet in the race.Case, who used to represent the Aloha State’s 2nd district, wasted no time in announcing that he is running in the special election. There is no word yet from Hanabusa, who has the backing of the pro-abortion-rights group EMILY’s List.“Neil’s mid-term resignation leaves an especially big puka in our delegation at a critical time for our Hawai’i and country,— Case wrote in an e-mail Friday afternoon. “With my seniority, experience, relationships and knowledge of current issues in Congress, I can and will hit the ground running from day one.—Also according to state law, as long as Abercrombie resigns his seat at least two months before the September primary in Hawaii, a special election will be called at least 70 days after when the vacancy occurs. Abercrombie did not say in his resignation letter when he will step down, but he added that he will make a more formal announcement Sunday.Democratic Congressional Campaign Committee Chairman Chris Van Hollen (Md.) released a statement praising Abercrombie and suggesting that the Congressman might have some role in the race to fill his seat.“I thank Representative Abercrombie for his extraordinary leadership and look forward to his help in filling the open seat in HI-01 with a Democrat who shares his commitment to fighting for the best interests of Hawaii’s middle class families,— Van Hollen said.