Oklahoma City, Ok. – Last week U. S. Senator Don Nickles said he has finally made his decision and will not run for a fifth term in the U. S. Senate. Now decisions are being made by those who might try to fill that seat. Yesterday Oklahoma Congressman Ernest Istook, Warr Acres republican, announced that instead of running for Nickles' seat he would seek another term in the U. S. House. Today Oklahoma City's 34th mayor, Kirk Humphries, said he would make his intentions known in three or four weeks. Humphries, a republican, was mentioned this summer by U. S. Senator Jim Inhofe to KCCU as a possible candidate if Nickles announced retirement plans. Last week former Stephens County resident State Treasurer Robert Butkin told KCCU he would probably decide within two weeks whether he would run for the seat. Oklahoma Attorney General Drew Edmondson, another democrat, also is considering the candidacy.