HARRISBURG - Six staffers on Sen. Rick Santorum's campaign - including an intern who tailed Democratic candidate Bob Casey Jr. in a duck costume - collected voter signatures to help place the Green Party on the fall ballot. The intern, petitions show, collected signatures from voters in five counties in one day. T.J. Rooney, the state Democratic Party chairman, and other Democrats disclosed details of the petition drive that they said offered further evidence of involvement from Santorum supporters to get Carl Romanelli, the Green Party's Senate candidate, on the ballot. Not only did Santorum aides help collect signatures for...