Sen. Patrick Leahy (D-Vt.) will preside over the upcoming impeachment trial of former President Donald Trump in place of Supreme Court Chief Justice John Roberts, he said Monday. Leahy, 80, was just sworn in as president pro tempore of the Senate. Both parties traditionally choose their oldest member to serve in the position, which is essentially a backup for the president of the Senate, whenever they gain a majority in the body. “The president pro tempore has historically presided over Senate impeachment trials of non-presidents,” Leahy said in a statement. “When presiding over an impeachment trial, the president pro tempore takes an additional special oath to do impartial justice according to the Constitution and the laws. It is an oath that I take extraordinarily seriously.” “I consider holding the office of the president pro tempore and the responsibilities that come with it to be one of the highest honors and …