CARSON CITY, Nev. - Jack Carter, the oldest child of former President Carter, said he's considering a run for the Senate, citing unhappiness with the federal government's handling of Hurricane Katrina. "I'm more concerned than ever with the way that the country is headed," said Carter, 58. Carter told the Las Vegas Review-Journal in Tuesday's editions that he's considering a challenge of Sen. John Ensign (news, bio, voting record), R-Nev., in 2006. He termed himself a social liberal with conservative Southern roots and a business background that taught him that "you pay for what you spend." "I'm very seriously exploring...