DELAWARE COUNTY Republicans have endorsed a federal prosecutor and decorated veteran of the first Gulf War to challenge Democratic U.S. Rep. Joe Sestak in this year's 7th Congressional District race. W. Craig Williams, who resigned this week as an assistant U.S. attorney in Philadelphia to run for office, got the nod last night from GOP leaders to take on Sestak, a retired Navy admiral serving his first term in Congress. He secured the party's endorsement without a vote. No other Republican candidates came forward at the Paxon Hollow Country Club. "Hopefully," Williams said, "the election in November goes about that...