WASHINGTON (AP) – The impeachment trial of President Donald Trump has opened in the Senate. House Speaker Nancy Pelosi says new evidence reinforces the need for senators to call additional witnesses. Pelosi warned senators not to become “all the president’s henchmen.” Trump derided the proceedings anew as a “hoax.” All the senators stood on Thursday and swore an oath of “impartial justice” as jurors for the historic proceeding. Chief Justice John Roberts presided in his black Supreme Court robe. The full trial will begin next week.