WASHINGTON — It’s the side of a trial that is unfamiliar to California Sen. Kamala Harris — listening silently as a member of the jury.
Harris, her California colleague Sen. Dianne Feinstein and 98 other senators returned to their wooden desks Wednesday for another marathon session in President Trump’s impeachment trial. It could be their routine for a while.
The third impeachment trial of a president in U.S. history comes with a set of strict rules for the senator-jurors: No cell phones. No talking. No coffee.
Harris knows the other side of the courtroom well, having argued criminal cases as a prosecutor in Alameda County and San Francisco. Now, she and other senators are expected to sit and listen as they fulfill their constitutional duty as jurors.
Senators, in the course of regular business, rarely linger on the floor past a vote or after delivering a speech. For the trial, they must stay for it all.
Feinstein couldn’t quite make it to the end Wednesday night — she left about an hour early. An aide said she wasn’t feeling well but would return Thursday.
Harris and many of her colleagues have described battling tedium as the two sides repeat their arguments for hour after hour. She said Wednesday that she’s felt an urge to interject at times: “The trial lawyer in me is active at every moment, having thoughts about the questions that should be asked.”
She was also candid about the toll of the long hours. Senators noticeably shuffled in their seats and took frequent bathroom breaks during the nearly 13-hour debate about trial rules, which started Tuesday and ended at 2 a.m. the next day.
“So far, so good,” Harris said as she left the chamber for a 15-minute recess Wednesday. “I definitely can’t sit down for too long, so from time to time I stand up. And then sometimes, I need a little chocolate.”
There have been rare moments of levity. On Tuesday, Harris fought back laughter as Democratic Rep. Hakeem Jeffries, a House impeachment manager from New York, quoted a line from the late rapper Notorious B.I.G. in response to a question from Trump’s counsel: “And if you don’t know, now you know.”
Harris said she and a few other senators “exchanged knowing glances,” adding, “At one point, I couldn’t control myself when he said well, ‘Now you know.’”
Feinstein left the trial about an hour before the session ended at 9:45 p.m. EST because she “was feeling under the weather,” according to a spokesman. Senators are expected to be present for the full trial, though brief absences are common.
At age 86, Feinstein is the oldest member of the Senate, and she ranks fifth in terms of seniority.
“She’ll be back tomorrow,” Feinstein’s spokesman, Tom Mentzer, told The Chronicle in an email.
Feinstein and many other senators have largely stayed off social media during the trial hours, but Harris’ Twitter account has remained active. She posted several video updates Wednesday.
In one update, minutes before the start of proceedings, Harris told followers it “was bananas” that Senate Republicans blocked all efforts to subpoena witnesses at the trial’s outset.
Feinstein, for her part, often takes notes during floor sessions. During a daytime break Wednesday, she said her notes include musings on the future of the country and how to protect its “long-term destiny.”
She was in the Senate for then-President Bill Clinton’s 1999 impeachment trial. But Feinstein said nothing like the allegations regarding Trump’s conduct in the Ukraine affair has happened in her 27 years in Washington.
“It really bears soul searching,” she said as she walked through the Senate hallway on a recess. “We don’t think enough, about America, our strengths, our weaknesses. I think we have to concentrate now on that if we want to remain the world’s leader.”
Both of California’s senators have remained focused on the push for witness testimony.
Feinstein rebuked Trump on Wednesday after he appeared to gloat about withholding subpoenaed documents from Congress. At a news conference in Davos, Switzerland, the president said, “Honestly, we have all the material. They don’t have the material.”
“This is even more reason for Republicans who want a fair trial to support Sen. (Chuck) Schumer’s request for documents and witnesses,” Feinstein said in a statement.
Harris said she’s eager to start asking questions — senators will have 16 hours next week to pose questions in writing to House impeachment managers and Trump’s defense attorneys. She said she expects the trial to last no more than two weeks.
“Aside from family, there probably aren’t many more things that are as important or as deserving of full attention as this proceeding,” Harris said. “This is a debate about the integrity of our system of democracy.”
Dustin Gardiner is a San Francisco Chronicle staff writer. Email: [email protected] Twitter: @dustingardiner