By Aaron Blake - 06/01/09 11:21 AM EDT
Coburn was expected to seek another term, but had kept remarkably quiet about his plans. He also hasn’t actively raised money, which led some to speculate that he wouldn’t run again.
Had Coburn opted not to run, Gov. Brad Henry (D), Rep. Dan Boren (D) and former Gov. Frank Keating (R) were considered possible candidates. Now that he is running, none of them are expected to run.
Coburn has pledged to serve no more than two terms, meaning the seat will be open in 2016.