HARRISBURG, Pa. (AP) — Republican David McCormick is entering Pennsylvania’s U.S. Senate race in his second bid for the office, this time to take on Democratic Sen. Bob Casey. McCormick’s announcement Thursday comes after he lost in last year’s Republican primary for Senate. McCormick made the announcement in a ballroom full of supporters at the Heinz History Center in Pittsburgh. Senate candidates in Pennsylvania will share a ticket with candidates for president next year in a state that’s critical to whether Democrats can maintain control of the White House and the Senate. A race between Casey and McCormick could be one of the nation’s most expensive and closely watched.