South Carolina Republican Lindsey Graham, one of the president’s fiercest defenders in the Senate, chuckled, bowed his head slightly and rubbed his left eyebrow.

Senate Minority Leader Charles E. Schumer and California Sen. Dianne Feinstein laughed and met the eyes of their knowing Democratic colleagues.

It was just after 6 p.m. Friday, just before a dinner break, and House managers were playing a montage of over-the-top statements by President Donald Trump on the Senate chamber’s temporary televisions.

“Nobody knows the system better than me,” Trump said in one clip. “I am the chosen one,” he said in another.

This was the fourth long day in the Senate chamber of the third presidential impeachment trial in U.S. history, and the 100 senators were finding ways to make the best of the stretch of time they had to spend with each other.

Ahead of dinner, a number of senators had their heads down reading or writing on paperwork that didn’t appear to have any connection to the House managers’ presentation.

Florida Republican Marco Rubio kept his head down and worked persistently on papers on his desk in the back row. 

At one point, Tennessee Republican Lamar Alexander left his seat to stand and lean against a railing in the back of the chamber. In front of him, GOP colleagues Ben Sasse of Nebraska and Bill Cassidy of Louisiana turned from some paperwork on their desks to greet him briefly, then turned their attention back to their papers.

As House manager Val B. Demings of Florida spoke in the afternoon, Tennessee Republican Marsha Blackburn held a stack of papers that she read through her bright orange glasses.

Others during the day appeared to be drafting letters, reviewing documents, or holding folded newspapers, including Virginia Democrat Mark Warner, Wisconsin Democrat Tammy Baldwin and Georgia Republican David Perdue.

Cellphones, banned from the Senate along with other electronics, began to make an appearance in the chamber.

As the senators returned from dinner, South Dakota Republican John Thune was among those seen with the contraband. A senior aide reminded him of the rule, so he quickly went to the Cloakroom to stash it.

As for the public gallery, there was a bit of what the Capitol Police might call a situation.

A visitor got through unusually tight security and into the gallery without surrendering his cellphone Friday afternoon, but a doorkeeper caught the offender: Former Senate Majority Leader Bill Frist.

At about 4:30 p.m., the erstwhile GOP senator from Tennessee was seated in the second row of the third-floor gallery reserved for senators and special guests when a doorkeeper came down the staircase and checked to see if he had electronics.

As a former senator, Frist was exempt from the usual security protocols that include going through a magnetometer. Frist handed over a device that appeared to be a cellphone, and the doorkeeper returned minutes later with a coat check card.

Glasses of milk and the media fascination with them were, sigh, still a thing.

At around 4:15 p.m., Iowa Republican Joni Ernst ordered a glass of milk from a page. When it was delivered to her desk, Ernst looked up to the press gallery and flashed a thumbs up and a big smile.

Sitting next to Ernst was Arizona Republican Martha McSally who muffled a laugh and to McSally’s right Missouri Republican Josh Hawley, too, flashed a smile.

The chamber received its first milk delivery roughly a half hour into Friday’s proceedings, to West Virginia Democrat Joe Manchin III.

Cory Booker was one of four senators who began the day with two glasses of water on his desk instead of one, and he must have been thirsty. The New Jersey Democrat dispatched both glasses within 10 minutes of the opening prayer and pledge. A Senate page promptly arrived with two more glasses.

While in the midst of jotting down copious notes, Jon Tester was handed a piece of paper from Delaware Democrat Chris Coons, eliciting a chuckle from the gregarious Montana Democrat.

Tester glanced back at Minnesota Democrat Amy Klobuchar — from whom the note originated and whose desk abuts Coons’ on the other side — resulting in the two sharing a smile.

Democratic manager Jerrold Nadler caused a mild stir on the Republican side of the chamber in the late afternoon as Democrats turned their attention to the impeachment article accusing the president of obstructing Congress.

“He is a dictator,” Nadler said of Trump, after a long speech outlining the president’s unprecedented “blanket defiance” of subpoenas and information during the impeachment inquiry.

Multiple GOP senators murmured to one another at the New York Democrat’s statement. Graham and Kansas Republican Jerry Moran exchanged a brief exchange and chuckle.

Hours later, during his closing remarks, lead impeachment manager Adam B. Schiff of California irked Republicans when he referenced a CBS News story with a headline that said Republicans were warned if they vote against Trump “your head will be on a pike,” saying he didn’t know if it was true.

Maine Sen. Susan Collins, one of the most vulnerable senators up for reelection this cycle, reacted first, mouthing “not true.” Shortly after other Republican senators started saying it aloud — even though senators are not supposed to talk during the trial — and echos of “not true” could be heard across the chamber.

Schiff later tried some levity with his audience. Chief Justice John G. Roberts, Jr., he said, is capable of making impartial rulings about matters dividing senators on questions of evidence, witnesses and executive privilege.

“How often do you get to overrule a justice of the Supreme Court?” Schiff asked them. Sen. Charles E. Grassley held up two fingers as lawmakers on both sides of the aisle chuckled at the question.

Several senators appear to be suffering from apparent colds. Among the afflicted are North Dakota Republican John Hoeven, Massachusetts Democrat Edward J. Markey and New Mexico Democrat Martin Heinrich, who let loose a handful of hearty sneezes into the crook of his left elbow.

Majority Leader Mitch McConnell prefers an old-school cleanup: After a particularly jolting sneeze early in the day’s proceedings, the Kentucky Republican recovered a handkerchief, wiped himself clean, folded the hanky into a foursquare, and slid it back into his right pocket.

New York Democrat Kirsten Gillibrand flagged down a page, who scurried off and returned 20 seconds later with a small tan envelope noticeably bulging at its belly.

Gillibrand concealed the envelope in her desk drawer and fumbled around inside it with both hands. In one swift, sweeping motion, she discreetly deposited a blue-green gum stick into her mouth and tossed the wrapper in the waste bin separating her desk from Hawaii Democrat Mazie K. Hirono’s.

Seat mates Ernst and Arkansas Republican Tom Cotton were the chattiest in the chamber early on, despite the stern daily warning from Sergeant-at-Arms Michael C. Stenger to “keep silent, on pain of imprisonment.”

There were signs of fatigue.

Ahead of the dinner break, Thune sat back in his chair gripping the pillars of his armrests and chewing deliberately while listening to the presentation. He then loosened up his neck making a circular motion.

West Virginia Republican Shelley Moore Capito neatly folded a red shawl and placed it on her lap.

At least 27 Senate desks were empty when Demings took the floor following a “15 minute” break that only a Senate time-keeper could argue was respected.

Lindsey McPherson, Niels Lesniewski and Chris Marquette contributed to this report.