Sen. Chuck Grassley (R-Iowa) administered the oath to Roberts.
Watch the swearing-in below:
Supreme Court Chief Justice John Roberts has sworn in all 100 senators for the impeachment trial against President Trump. The senators will serve as jurors at the trial. https://t.co/lPZYvMbmvc pic.twitter.com/bPITYn78Io— CNN (@CNN) January 16, 2020
After Roberts took the oath, Grassley could be overheard saying, “God bless you.”
Roberts then swore in all the senators present.
“Do you solemnly swear that in all things appertaining to the trial of the impeachment of Donald John Trump, President of the United States, now pending, you will do impartial justice according to the Constitution and laws so help you God?”
The senators were then called to the front of the chamber in groups of four to sign an oath book.
Roberts will preside over the trial and have the power to weigh in on motions filed during the proceeding.
Immediately after all the senators present were sworn in, Roberts began his duties as the presiding official as Senate Majority Leader Mitch McConnell (R-Ky.) introduced a motion to adjourn until Tuesday at 1 p.m.