WASHINGTON, Jan. 5 (UPI) -- Former South Dakota Republican congressman John Thune is expected to announce Monday he will run for the U.S. Senate. Thune is scheduled to speak at the Lincoln County, South Dakota, GOP's Lincoln Day Dinner. Republican sources inside the state say they expect him to make it official that he will challenge Senate Minority Leader Tom Daschle in the 2004 election. The possibility that he would challenge Daschle, a leading critic of the Bush administration, has been widely forecast since Thune lost a bid for the Senate in 2002 by just over 500 votes to Democratic...