For more than a month since Senator Mitch McConnell, Republican of Kentucky, entered the hospital, Washington has been on something of a death watch for the frail 84-year-old former leader, who has provided no information about his condition.
So the news of the sudden death on Saturday night of another lawmaker more than a decade younger, Senator Lindsey Graham, Republican of South Carolina, came as a particular shock to his colleagues. Many of them are around the same age as Mr. Graham, who died two days after his 71st birthday, and did not think of his age or health as an issue.
Together, Mr. McConnell’s lengthy hospitalization and the unexpected passing of Mr. Graham offered the latest reminders that the Senate is run by a geriatric class of lawmakers — some old, and some very old — many of whom hang on to their positions of power long past their primes, and long after the age when most Americans have retired.
Mr. Graham was energetic, omnipresent and in the midst of a re-election campaign that he had been expected to win handily for another six-year term. His age was barely remarked upon in the Senate, an institution that is sometimes only half-jokingly referred to as the world’s most prestigious nursing home.
There, the average age is just under 66, and more than one-third of members are Mr. Graham’s age or older.
He served alongside lawmakers including Senator Charles E. Grassley, Republican of Iowa, who at 92 is third in line to the presidency, leads the powerful Judiciary Committee and proudly reminded voters in a social media post earlier this month that he has been farming corn since the civil rights movement. Senator Bernie Sanders, the Vermont independent who remains a major force driving the Democratic Party, is 84, one of seven octogenarians in the chamber, including Mr. McConnell, who has undergone a steep physical decline in public for years.
Some of the tributes that rolled in on Sunday from colleagues came from people who had embarked on their careers when Mr. Graham was still in high school.
“When we last spoke, he was as enthusiastic and exuberant as I’ve ever seen him,” Senator Richard Blumenthal, Democrat of Connecticut, said in a statement.
Mr. Blumenthal is 80.
Still, Mr. Graham’s unexpected death after three decades in Congress, from what his office described only as a “brief and sudden illness,” was the latest reminder that the institution celebrates seniority and is built to avoid raising questions about incumbency and accumulated power.
Even as remembrances poured in, so did calls for change to what many people view as a broken system that is making government more dysfunctional.
“The constant deaths in office we’ve seen over the last few years aren’t shocking when you have a gerontocracy where too many elected officials would rather die at their desks than let anyone new fix people’s problems,” said Rohan Patel, the executive director of Majority Democrats, a political action committee that backs the next generation of Democrats and soon plans to roll out a campaign targeting older lawmakers.
Mr. Patel added: “If you haven’t worried about child care in 50 years, applied for a job in 40 or bought a house in 30, you cannot understand the problems Americans are facing today, and the rest of us are paying the price.”
Even as the two oldest presidents in history, former President Joseph R. Biden, Jr. and President Trump, have in recent years pushed the issue of aging in office into the forefront of voters’ minds and the political conversation, this Congress is the oldest in modern history.
Of the 530 voting members of the House and Senate, 131 of them — nearly a quarter — are 70 or older.
The average retirement age for men is 64, and about 62 for women, according to the Center for Retirement Research at Boston College.
Rahm Emanuel, the former Chicago mayor and White House chief of staff, who is eyeing a presidential run in 2028, has long called for mandatory retirement at 75 for people serving in all three branches of government, as well as for cabinet secretaries.
“You’re not hitting your stride at 78,” Mr. Emanuel said in a brief interview on Sunday, following the news of Mr. Graham’s death. “The United States government at all levels look like the Brezhnev bureau from the Soviet days.”
Mr. Emanuel recalled working with former Senator Dianne Feinstein, Democrat of California, in her prime, when she played a key role in passing the assault weapons ban. That made it all the more painful, he said, to witness her in her final, deteriorating days before her death in office, when “she didn’t know she was a United States senator,” Mr. Emanuel said.
Mr. Graham was the first senator to die in office since Ms. Feinstein in 2023, at the age of 90, after a long physical and mental decline that tarnished her legacy.
Mr. Emanuel said that after the age of 75, the task at hand for once-great legislators was simple: “Get out of Washington.”
But aging lawmakers are often reluctant to give up power, and view their experience as an asset, not a liability, even as they enter life’s final chapters.
In the Senate, there is little appetite for questioning incumbency, and staff aides are invested in keeping their aging bosses in place.
Strom Thurmond, the South Carolina Republican, famously hung on until past his 100th birthday. Robert C. Byrd, the West Virginia Democrat, died in office at age 92 after 51 years in the Senate. Despite serious medical issues, Thad Cochran, Republican of Mississippi, ran for re-election at 76, with the prospect of leading the powerful Appropriations Committee too good to pass up — though he later resigned before the end of his term, citing his failing health.
When the Senate returns from its holiday break on Monday, Republicans will be mourning Mr. Graham’s passing while still remaining in the dark about the prognosis of Mr. McConnell. While his aides have refused to divulge any information about his health status, emergency responders reported performing CPR on an unconscious individual suffering cardiac arrest at the senator’s Washington address on the morning he was hospitalized.
On Sunday, a spokesman said there was no update, only that Mr. McConnell was continuing his recovery in the hospital.
Matt Zdun contributed reporting.
