The presidential line of succession isn’t top of mind for most senators, but Saturday’s shooting at the White House Correspondents’ Association dinner changed that.

Sen. Sheldon Whitehouse, who was in the ballroom, said about the rapid law-enforcement response pulling Cabinet members and top congressional leaders: “They were definitely tracking the line-of-succession people and getting them outta there.”

Sen. Josh Hawley, who was not in attendance, recalled hearing the news and thinking about President Donald Trump, Vice President JD Vance and high-level members of the Cabinet all in the same venue. “A lot of people in the room,” Hawley said.

On a farm in northern Iowa, about 1,000 miles away, an elite security team for the U.S. Capitol Police also got alerted about the shooting and closely monitored the events.

“I have a detail with me, and they kept me informed,” Sen. Chuck Grassley recalled in a brief interview this week.

At that moment, the 92-year-old Republican was the only one of the first eight members of the presidential line of succession not in the ballroom of the Washington Hilton, where a potential assassin was tackled carrying a long gun, a handgun and some knives.

That event became the type of disaster that some experts have been warning about for years: A quirk in senatorial custom has left the nation with the possibility of an 80- or 90-something-years-old senator becoming president.

Should the president, vice president and House speaker all become incapable of serving, the next in line is the president pro tempore of the Senate.

That mostly honorific post is now held by Grassley, who launched his political career during the Eisenhower administration and won his first race for the Senate in 1980.

Over the last 20 years, six senators have held the “pro temp” position, and in all but four of those years, that senator was 80 or older.

The name derives from the Latin word “for the time being,” because the position was meant to serve as a temporary replacement for the vice president presiding over the chamber. Grassley is in his fourth year in the office across two separate terms as pro temp, about the same tenure as others who’ve served in the position. He could serve into January 2029 — when he will be 95 — if Republicans maintain the majority in November’s elections.

Constitutional experts say America has reached the point of alarm over this situation, suggesting that the last few years have shown the proclivity for political violence — along with back-to-back elderly presidents — makes this third-in-the-line-of-succession position one that should be changed.

“We have reason to worry. Threats to presidents are to be taken seriously. Choosing to do nothing at this point is beyond constitutional malfeasance,” said Steven S. Smith, a political science professor emeritus and expert on Senate history.

Smith has written extensively on how Senate leadership positions evolved over the late-19th century and first half of the 20th century. In the early days, the president pro temp was the only leadership position in the chamber and often prompted competitive votes among senators for the position.

In the 1790s, a law set the succession from the vice president to the Senate pro temp, then the House speaker. But in 1947, when Franklin D. Roosevelt’s death led to changes in the succession law, President Harry S. Truman’s close bond to House Speaker Sam Rayburn led him to suggest flipping the order and demoting the Senate’s pro temp, according to the chamber’s history site.

Around that time, a gentleman’s agreement created the custom by which the longest-serving senator of the majority would become pro temp.

Today’s senators expressed some level of concern about this nightmare scenario, given Saturday’s events, but many aren’t sure how to fix it.

“I don’t know the answer to that,” Hawley, 46, in his second term, said. “I guess we could do that without changing the Constitution. I don’t know.”

“It’s a valid concern,” said Sen. Brian Schatz, 53, poised to become the Democratic whip, the No. 2 leadership post, next year. “The backup president is 90-something.”

Smith believes that the easiest fix is for the Senate to choose a younger, more dynamic person for the pro temp position, as happened in the 19th century.

But the position has evolved from the latter half of the 20th century, when the most important duties were opening the chamber’s sessions and signing bills before sending them to the White House.

After the Sept. 11, 2001, terrorist attacks, security details got assigned to the pro temp officeholder. And, over the years, the Senate gave the post a large budget — regularly topping $600,000 the past eight years — and prime corner office space in the Capitol.

It’s now considered a prized position that senators have spent decades in pursuit of, so those older, more powerful senators aren’t likely to give up those plum benefits.

Another fix would be to simply amend the 1947 line-of-succession law and replace the pro temp with the Senate majority leader, someone who is regularly elected every two years by peers and would almost certainly be in better health than the president pro temp.

But Norman Ornstein, a congressional scholar who has become an expert on the continuity of government, has suggested that the Founding Fathers originally wrote that the succession should flow to an “Officer” without ever mentioning Congress.

Moreover, in his argument that only Cabinet members or other senior officials from the president’s team be considered, Ornstein has noted that would eliminate the possibility of the executive branch changing parties due to an emergency disaster.

“Voters choose a president and the idea is anathema that an assassination or a death in office — a double death, including that of the vice president — could put into the presidency someone who does not represent the party that was chosen by voters in the presidential election,” Ornstein wrote in a Fordham Law Review piece in late 2022. “That ought to leave all of us uneasy.”

Senators feel a bit awkward talking about changing the succession laws because of the often revered status enjoyed by these elder statesmen.

Grassley has chaired several key panels, currently the Judiciary Committee, and he went 27 straight years without missing a vote until late 2020 when he contracted COVID-19.

Sen. Patty Murray, who preceded Grassley as pro temp, has chaired three committees and did two stints as a campaign committee chief. At 72 in January 2023, Murray became the youngest person to hold the position this century. She was also the first female to hold the post.

The outside experts take a more hard-nosed, maybe realistic, approach to the matter.

Ornstein believes that the potential for long stretches with anyone serving as an interim president, without having been voted into the post by voters, is a mistake.

“We ought to make sure that we have protection for our country under terrible circumstances. We ought to seriously consider having some kind of special-election provision so that we don’t have potentially four years without the public’s choice being in place,” he wrote.

“If changing the Succession Act won’t happen, the Senate should consider adopting a rule that sets an age limit for a president pro temp,” Smith said.

Smith noted that Saturday’s event drew Vance and House Speaker Mike Johnson, along with the secretaries of state, treasury and defense, the attorney general and the interior secretary — seven of the first eight in succession after Trump.

“At a minimum, serious consideration should be given to more stringently limiting which government officials can be together in a public venue,” he said.

For now, senators are relieved that a national disaster was averted and no one had to consider the possibility of a “President Grassley.”

“I’m glad Chuck wasn’t there,” Hawley said. “I’m glad everybody was safe.”