Oklahoma Senator Tom Coburn, a Republican known for his fiscal conservatism and friendship with President Obama (despite calling for his impeachment), announced Thursday night that he’s stepping down at the end of this congressional session. Rumors about Coburn’s retirement have been circulating since he revealed that he’s battling prostate cancer again, but he said that’s not why he’s leaving office. “This decision isn’t about my health, my prognosis or even my hopes and desires,” Coburn said. “As a citizen, I am now convinced that I can best serve my own children and grandchildren by shifting my focus elsewhere.” The former obstetrician has always said he would not seek a third term, but this cuts his tenure short by two years. The special election to serve out the remainder of his term is unlikely to change the balance of power in Congress, since Oklahoma hasn’t had a Democratic senator in two decades.