WASHINGTON — “How am I feeling?” Justice Ruth Bader Ginsburg asked on Saturday, articulating the question on the minds of nervous liberals and many of the 4,000 people who had stood in line for hours to see her interviewed in a cavernous convention center.
“This audience can see,” she said, “that I am alive.” The statement was greeted with thunderous applause. “And I am on my way to being very well,” she added as the room quieted down.
Justice Ginsburg was assisted as she climbed the stairs to the stage, at a book festival sponsored by the Library of Congress. But she was relaxed, alert and cheerful in discussing her life and work.
The interview was part of a remarkably busy public schedule for Justice Ginsburg after the Supreme Court announced last week that she had been treated for pancreatic cancer. The appearances have given liberals hope that she will remain on the court longer than President Trump will be in the White House, allowing a Democrat to name her successor.
Justice Ginsburg, 86, was in Buffalo on Monday to receive an honorary degree. She is scheduled to be in North Little Rock, Ark., on Tuesday. Demand for tickets was so high that the event was moved to a sports arena with a capacity of about 18,000.
Nina Totenberg, the NPR correspondent who interviewed Justice Ginsburg on Saturday, said there were another 16,000 people on the waiting list for her appearance in Arkansas.
The appearances tend to follow a pattern: a standing ovation from an adoring crowd, followed by questioning from a sympathetic interviewer. Justice Ginsburg tells nicely honed anecdotes about her earlier career as a feminist professor and litigator, her marriage, the Supreme Court and the law. She lands a couple of jokes. She describes her unlikely friendship with Justice Antonin Scalia, who died in 2016.
But the tone was a little different on Saturday in light of her recent medical setback.
“I love my job,” she said. “It has kept me going through four cancer bouts. Instead of concentrating on my aches and pains, I just know that I have to read a set of briefs and go over a draft opinion. Somehow, I have to surmount whatever is going on in my body and concentrate on the court’s work.”
The latest string of public appearances was scheduled before the announcement that Justice Ginsburg had undergone three weeks of radiation treatment for a malignant tumor on her pancreas. “The tumor was treated definitively and there is no evidence of disease elsewhere in the body,” the court’s statement said.
This was Justice Ginsburg’s fourth brush with cancer, following surgery in December to remove two malignant nodules from her left lung, surgery for early-stage pancreatic cancer in 2009 and treatment for colon cancer in 1999.
Medical experts said the court’s statement about Justice Ginsburg’s recent tumor was vague enough to make it difficult to pinpoint her precise diagnosis, much less to speculate on how her disease might progress.
But most experts agreed that the tumor, described as a localized malignant tumor, was likely to have been a new lesion in the pancreas, rather than a recurrence of the earlier pancreatic cancer or a cancer from another organ that had spread.
Though surgery is typically the preferred treatment for a tumor in the pancreas, Justice Ginsburg appears to have chosen radiation, which is generally less disruptive. Surgery can be grueling and tough on someone of Justice Ginsburg’s age and health.
A stent was inserted in Justice Ginsburg’s bile duct, the court’s statement said, indicating that the tumor was in the head of the pancreas, according to experts. Surgery to remove that kind of tumor is a complex four- to 12-hour procedure with a high rate of complications and even death. It often leaves the patient with diabetes and entails a long recovery period.
“It’s a surgery we do often, but you’re in the hospital for a week, and you’d not be 100 percent yourself for six to eight weeks, and maybe three months,” said Dr. Daniel Labow, the chairman of surgical oncology at Mount Sinai Health System.
The type of radiation treatment Justice Ginsburg had, called stereotactic ablative radiation therapy, concentrates radiation on the tumor, limiting damage to the surrounding organs, and is generally less disruptive to patients’ lives.
Justice Ginsburg is loath to miss work or cut back on her public schedule. Despite her health setbacks over the years, she had never missed an argument in her 25 years on the court until January, when she was absent from the bench for two weeks after her lung surgery. She participated in the cases argued then by reading briefs and transcripts.
On Saturday, Justice Ginsburg discussed only one recent Supreme Court decision, the ruling in June that determined federal courts are powerless to address partisan gerrymandering, the practice of drawing voting districts to aid the party in power.
It was a 5-to-4 decision, and Justice Ginsburg and the other three liberal members of the court were in dissent. She denounced a practice that she called rigged elections. “That’s not the way a democracy should run,” she said.
Were Justice Ginsburg to leave the court during Mr. Trump’s first term, it would give him an opportunity to name a third justice. The last president to appoint more than two justices in his first term was Richard M. Nixon, who put four on the court from 1969 to 1972. Those appointments spelled the end of the liberal court that had been led by Chief Justice Earl Warren and created a conservative majority that remains to this day.
The current court is closely divided, with five Republican appointees and four Democratic ones. A third Trump appointee would not only make the balance more lopsided but would also almost certainly move the court’s ideological center to the right.
On Saturday, Justice Ginsburg seemed committed to staying on the job while marveling at her celebrity. “It’s amazing,” she said. “At the advanced age of 86, everyone wants to take a picture with me.”
Carla Hayden, the librarian of Congress, said she had been inclined to introduce the justice as “the Beyoncé of jurisprudence.” But Justice Ginsburg had a different idea, Ms. Hayden said, indicating a preference for “the J. Lo of jurisprudence.”
A little later, Justice Ginsburg described meeting Jennifer Lopez and Alex Rodriguez in her judicial chambers. She shared with the celebrity couple her mother-in-law’s secret for a happy marriage: “It helps sometimes to be a little deaf.”