In this April 29, 2008 file photo, former Rep. Jim Slattery, D-Kan., announces his candidacy for the U.S. Senate during a rally in Topeka, Kan. After spending more than a decade in Washington making millions of dollars as a lawyer and lobbyist for one of the nation's most prestigious law firms, the former Democratic congressman from Topeka is jumping back into the political arena in a bid to unseat Sen. Pat Roberts, R-Kan. (AP Photo/Orlin Wagner, File)

Sen. Pat Roberts, R-Kan., speaks during a hearing in Washington Win this April 18, 2007 file photo. "It was a mess," said Roberts, who portrayed the president in the 2002 "Crimson Sky" exercise - A simulated outbreak of foot and mouth disease. The exercise ended with riots in the streets after fictional National Guardsmen were ordered to kill tens of millions of farm animals, so many that troops ran out of bullets. In the exercise, the government said it would have been forced to dig a ditch in Kansas 25 miles long to bury carcasses. Protests broke out in some cities amid foot shortages. (AP Photo/Dennis Cook, File)