HARRISBURG, Pa. — Donald Trump on Saturday endorsed Doug Mastriano in Pennsylvania’s Republican primary for governor, siding with a far-right candidate who was outside the U.S. Capitol during the Jan. 6 insurrection and has worked with determination to overturn the results of the 2020 presidential election. Mastriano was already leading a crowded field of contenders, and the former president’s endorsement puts him on even stronger footing heading into Tuesday’s primary. But there are growing fears from party leaders that Mastriano, a state senator and retired U.S.