Republican incumbent: John Barrasso
Democratic candidate: Nick Carter
Barrasso, 56, was appointed to the Senate by Governor David Freudenthal, effective June 25, 2007, to replace the late Craig Thomas. Under an unusual state law, the Democratic governor was required to appoint a Republican to the seat, because Republican Thomas had won the most recent general election for it. Barrasso has served as a state senator. In 1996, he lost the Republican primary for Wyoming's other Senate seat.
Carter, 44, is an attorney making his first run for elective office.
The winner will serve the remaining four years of the term to which Thomas was elected in 2006.
Real Clear Politics reports a poll showing Barrasso ahead by 24 points.