Senators on both sides of the aisle were showing signs of fatigue as former President Trump’s impeachment trial stretched into its third day.

At least 18 GOP senators were missing from their seats during the second hour of arguments. Even some Democrats appeared to be getting weary.

Sen. Bernie Sanders (I-Vt.), 79, was spotted slumping over at his desk, not turning his head to watch videos at one point as House impeachment managers continued to make their case about Trump's statements and actions surrounding the Jan. 6 attack on the Capitol.

Sen. Joe Manchin (D-W.Va.) was at his desk, tapping his shoes and knees together as he propped himself up by his elbows in an armchair.

Sens. Cory Booker (D-N.J.) and Kirsten Gillibrand (D-N.Y.) stood at the back of the chamber, leaning against the marble columns to take a break from hours of sitting.

Democratic strategist David Axelrod warned House managers not to over-argue their case a day after they presented new, harrowing video of the Capitol siege.

“Wondering if the managers would have been smart to quit and simply sum up with the lack of remorse argument after their incredibly tight powerful case yesterday?” he tweeted.

Sen. James Inhofe (R-Okla.), a staunch Trump ally, said the managers’ argument is losing steam the longer it goes on.

“It's just redundance, the same thing over and over again,” he said. “To me, the more you hear it, the less credibility there is in it."

Senators heard four hours of debate over the constitutionality of the trial Tuesday and nearly seven hours of presentations from House managers Wednesday, which featured previously unreleased security camera footage of the Capitol attack.

Senate Majority Whip Dick Durbin (D-Ill.) predicted at 2:15 p.m. Thursday that the managers would begin wrapping up soon.

Even Senate Majority Leader Charles Schumer (D-N.Y.), who is known for his energy and focus, showed a lapse in concentration when he asked for the House to stand in a 15-minute recess. Colleagues reminded him in a chorus that he was sitting in the Senate, not the lower chamber.

Two senators, Patty Murray (D-Wash.) and Shelley Moore Capito (R-W.Va.), had blankets on their laps to stay warm.

Sen. Tim Kaine (D-Va.) said that repeatedly reliving the violence and chaos on Jan. 6 is draining.

“It’s emotionally more draining than hearing the transcript of a call with a Ukrainian political leader,” he said, comparing it to Trump’s first impeachment trial in 2020.

Senators are hoping to wrap up the trial as soon as Saturday, earlier than initially expected.

Several expressed little desire to hear from new witnesses, something senators will debate after a question-and-answer session that follows the defense portion of the trial. Trump's attorneys are allotted 16 hours to present their counterarguments to House impeachment managers.

His lawyers are not expected to use all 16 hours.

“I think the case has been made. I don’t know what witnesses would add,” said Sen. Angus King (I-Maine).