SEN. Bob Casey (D-Pa.) says President Obama has a secret weapon — on the basketball court. “I love to play with him, but I’m never on the winning team,” Casey told the crowd at Rosie O’Grady’s on West 46th the other night at his re-election fund-raiser thrown by one-time Hugh Carey chief of staff Jim Cunningham. Casey said Obama always says, “I’ll pick first. I pick Reggie,” meaning Reggie Love, the president’s “body man” who played basketball for Duke. “Reggie protects and feeds the president on the court, and together they cream the rest of us. But it’s great fun.” Also on hand were Jim Gill, Jerry Crotty, Alfred E. Smith IV, Tonio Burgos and Bill Cunningham.