HARRISBURG, Pa. (AP) – The Republican field of candidates aiming to capture Pennsylvania’s open U.S. Senate seat is churning. Out is Sean Parnell, the candidate endorsed by former President Donald Trump. Parnell’s exit is reshuffling the race. Getting in might be a couple guys who are relative unknowns to many party figures. First, there’s Mehmet Oz, the cardiac surgeon and host of TV’s “Dr. Oz Show.” He’s a longtime New Jersey resident. The other is David McCormick, a Connecticut resident who runs one of the world’s largest hedge funds, but grew up in Pennsylvania. The campaign could determine Senate control in next year’s election.