Rudolph W. Giuliani, the former New York City mayor, visited Westchester County today to speak on behalf of one of his new clients, Entergy Nuclear Northeast, as it prepares for an antiterrorism drill at its Indian Point nuclear power complex. The visit was part of an elaborate presentation by Entergy that blended the thrills of a summer action picture — an M-16 semiautomatic rifle firing blanks at an Indian Point security officer — and Mr. Giuliani's star power. It seemed designed to take back some of the attention that has lately focused on Entergy's critics, who have attacked the nuclear...