Updated at 2:57 p.m. ET
Sen. Patrick Leahy, D-Vt., will preside over former President Donald Trump's trial in the Senate, a Senate source tells NPR. Leahy, 80, is the president pro tempore of the Senate, a constitutional role given to the longest-serving lawmaker in the majority party. The president pro tempore is third in the line of presidential succession, after the vice president and House speaker.
"I have presided over hundreds of hours in my time in the Senate," Leahy told reporters. "I don't think anybody has ever suggested I was anything but impartial in those hundreds of hours."
Leahy added: "I'm not presenting the evidence. I am making sure that procedures are followed. I don't think there's any senator who over the 40-plus years I've been here that would say that I am anything but impartial in voting on procedure."
Chief Justice John Roberts presided over President Trump's first impeachment trial, but now that Trump is a former president, Roberts is not constitutionally obligated to preside.
House impeachment managers will deliver the article of impeachment to the Senate Monday evening, and the trial is scheduled to begin the week of Feb. 8.
On Jan. 13, Trump became the only president in U.S. history to be impeached twice by the U.S. House of Representatives. House Democrats brought one article of impeachment — "incitement of insurrection" — related to remarks he made to a crowd loyal to him Jan. 6 that resulted in a fatal riot at the U.S. Capitol.
Trump, the first one-term president since George H.W. Bush in the 1990s, lost the November election to Biden, but has repeatedly and baselessly challenged the results citing little or false evidence.