South-central Kansans are a tough crowd for a Democratic president, even one whose mother was born here and whose administration oversaw the killing of Public Enemy No. 1. In a SurveyUSA poll, sponsored by KWCH, Channel 12, and conducted last Monday, 56 percent of those surveyed in the Wichita and Hutchinson area said they disapprove of the job Obama is doing as president. That was only a 5-percentage point improvement since mid-April. In other questions, 62 percent said it was appropriate to celebrate Osama bin Laden's death, 52 percent said it was right to bury him at sea, and 44 percent said bin Laden's death would make the world safer long term.Nationally, Obama received a significant bump in his ratings following the killing of bin Laden, with 57 percent approving of his job performance in the latest New York Times/CBS News poll. That's up from 46 percent last month.