Thomas won election to his third term in the Senate this past November; two days after the election, he announced he had been diagnosed with acute myeloid leukemia. He was treated with chemotherapy and returned to the Senate in December, but his cancer eventually worsened and when he died he was at the National Naval Medical Center for a second round of treatments. On Monday afternoon he was reported to be in serious condition, battling an infection as well as the leukemia.
Thomas was originally elected to the House of Representatives in a special election in 1989; he replaced Vice President Dick Cheney, who left Congress to become secretary of defense in the administration of George H.W. Bush. Thomas was elected to the Senate in 1994, and won his subsequent two elections, in 2000 and 2006, by commanding margins over his Democratic opponents.
Wyoming Gov. Dave Freudenthal, a Democrat, is responsible for choosing Thomas' replacement. The seat will stay Republican, however -- under Wyoming law, the state Republican Party will provide Freudenthal with a list of three potential nominees from which to choose.