Former Massachusetts governor Bill Weld, who is challenging President Trump for the Republican nomination next year, on Monday accused him of “treason” for pressing the leader of Ukraine to investigate former vice president Joe Biden and his son. Weld’s comments came in response to reports that Trump repeatedly brought up investigating Biden, who is seeking the 2020 Democratic nomination, and his younger son, Hunter, in a July call with Ukrainian President Volodymyr Zelensky. “Talk about pressuring a foreign country to interfere with and control a U.S. election,” Weld said during an appearance on MSNBC’s “Morning Joe.” “It couldn’t be clearer,...