WASHINGTON >> He sternly challenged one of President Donald Trump’s nominees testifying in a Senate conference room. He discussed tax policy during lunch with members of the Democratic caucus. He displayed photographs of his trip to hurricane-ravaged Puerto Rico on the Senate floor. And he serenaded a smiling Sen. Ben Cardin, D-Md., on his birthday.

Like a frenzied tourist eager to not miss anything, Sen. Robert Menendez, D-N.J., buzzed around the Capitol on Oct. 5. It was his first time back in Washington since his federal corruption trial began a month ago, and he was eager to cram in as much as he could.

“It’s been a packed day,” said Juan Pachon, the lone aide accompanying Menendez. He turned as he saw the senator make his way toward a stairway. Menendez is a member of the Senate Foreign Relations Committee, and a meeting was starting in 10 minutes. Pachon chased after him.

“I haven’t even had breakfast.”

It was 2 p.m.

Instead of occupying his Senate office, Menendez has been occupying the defendant’s chair in a courtroom in Newark, where his slow-moving trial is stretching into its fifth week. He is accused of abusing his office to help his friend and co-defendant, Dr. Salomon Melgen, in exchange for luxury gifts and political contributions. Both men have denied the charges.

But on Oct. 5, a rare confluence of Senate activity and a court recess for a Jewish holiday gave Menendez an opportunity to return to Washington, his day a flurry of activity, notable even for the usually bustling senator.

“Whenever I get a chance to come back, I pack in as much as I can,” he said in an interview squeezed between a floor speech and a vote.

Menendez’s hectic schedule underscores an effort to show that although he may be fighting to stay out of prison, he is still fulfilling his senatorial duties. His office churns out a steady stream of news releases — 57 since the trial began — and has started new social media channels that feature supporters declaring how Menendez has helped them.

He has trumpeted bills that he has been able to push along his month, including one on human trafficking, and he has taken part in certain votes by proxy.

Menendez is waging a battle on two fronts: While he is defending himself in a federal courtroom, he is also trying win in the court of public opinion. The senator faces re-election in 2018, and a recent Suffolk University/USA Today poll found that only 20 percent of New Jersey voters have a favorable view of the senator.

Menendez is confident of his innocence and said that he had “no doubt that upon exoneration” his poll standing would rebound, especially when voters realized the work he had done even while on trial. His numbers will rise, he said, and “we’ll be re-elected.” He declined, however, to discuss the trial.

He arrived in Washington late Oct. 4 on an Acela train and went straight to a meeting about Iran in the White House situation room with Lt. Gen. H.R. McMaster, the national security adviser. Then he headed to a conference center on Capitol Hill to deliver a speech about a program that protects young undocumented immigrants from deportation.

After a long absence, Menendez, a familiar face in the Capitol since his election as a U.S. representative in 1993, seemed determined to prove he still had his Senate legs.

Although he announced at a news conference in Newark on Wednesday that he was heading to Washington, Menendez’s arrival still caused a stir. Congressional aides and journalists, crowding a second-floor corridor, murmured and nodded after Menendez emerged from an elevator.

“Bob’s here?” Sen. Cory Booker, D-N.J., said, after he was told why there were more reporters than usual at the Foreign Relations Committee meeting.

He turned and made a beeline toward the front of the room, waiting patiently for Menendez to finish talking to Corker. The two men embraced and shook hands.

Menendez’s office has been working especially close with Booker’s staff during the trial. The senators speak frequently — “not every night, because I think I would wear my welcome thin,” Menendez joked — and their staffs confer daily.

Despite the corruption charges, Booker has been steadfast in his support of Menendez, contributing to his legal defense fund, showing up for the trial’s opening statements and offering unlimited praise (“Bob Menendez never stops working for New Jersey” has become a regular refrain).

In a politically charged era, an indictment hanging over a senator could lead to a lonely day in the Capitol. But when he wasn’t running to meetings, Menendez received warm greetings from many colleagues: Sen. John McCain, R-Ariz., hugged him before a floor vote; Corker opened a morning committee meeting by telling him, “We’re glad to see you here”; and Sen. Tim Scott, R-S.C., interrupted an interview to greet Menendez.

“Let me just say hello right here,” he said, putting his arm around Menendez.

“I missed you at breakfast,” Menendez said.

“I was about to say the same thing,” Scott said as he left. “Look forward to seeing you when you’re back.”

In fact, Menendez’s trip was brief — the Senate was working only Thursday — and his trial resumes Tuesday, following the Columbus Day holiday.

While Menendez was clearly happy to be on Capitol Hill, and his step certainly had a more assertive pace than his slower loaf around the fourth floor of the federal courthouse in Newark, he stressed that even during the trial he had been focused on his job.

“I’m engaged with senior staff and colleagues as I would if I were physically here talking to them, but I’m talking to them on the phone,” he said. “So the only thing that is different from what I normally would be doing or not is my ability to cast votes on the committee.”

Indeed, subcommittee votes can be taken by proxy by Menendez’s staff, but full committee and floor votes have to be taken in person. In place of his votes, Menendez has offered what are recorded as “official explanations,” detailing how he would have voted had he been present.

His listed reason for missing every floor vote: “I was unavoidably absent.”

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