Where John Kelly’s Departure Fits in the History of Turnover Among Top Presidential Advisers

After announcing Saturday that his Chief of Staff John Kelly would be leaving at the end of the year, President Trump is on the hunt for someone new to fill the role. While this particular change sets a new record for most chiefs of staff within the first 24 months of an administration, the hiring phase is a position with which Trump is familiar, as the top levels of his Administration already boast a 62% turnover rate.

Kelly’s role had shrunk over his time in the White House as he found himself at odds with other members of the President’s inner circle, such as Jared Kushner and Ivanka Trump. But while the rate of personnel changes in Trump’s time is high, that kind of clash isn’t exactly new in presidential history.

There are plenty of examples of Cabinet members and members of a president’s inner circle butting heads, usually over conflicting world views. In the first presidential Cabinet, Alexander Hamilton and Thomas Jefferson famously fought for George Washington’s attention, with Hamilton advocating for a strong central government and Jefferson for a weaker one that favored states rights. And more recently, during George W. Bush’s administration, Secretary of State Colin Powell and Secretary of Defense Donald Rumsfeld clashed over how to rebuild Iraq after the fall of Saddam Hussein.

Aside from substantive disputes, “overlapping responsibilities” can also trigger clashes — especially between the National Security Advisor, the Secretary of State and the Secretary of Defense — according to K. Ward Cummings, author of Partner to Power: The Secret World of Presidents and Their Most Trusted Advisors. For example, what TIME called “intramural bickering” between Jimmy Carter’s National Security Advisor Zbigniew Brzezinski and Secretary of State Cyrus Vance meant that “almost every issue provoked a fight.”

Such conflict isn’t always bad. In fact, experts say one reason Abraham Lincoln’s Cabinet worked so well was precisely because he chose people who had run against him in 1860, emphasizing smarts over loyalty. He even repeatedly refused to fire Treasury Secretary Salmon P. Chase, who trashed the president repeatedly, because he believed Chase was the most qualified man for the job, saying, “I should despise myself if I allowed personal differences to affect my judgment of his fitness for the office.”

But sometimes it does precipitate staff changes.

Those changes can be perceived as positives — Andrew Jackson once defended his Cabinet’s having essentially disintegrated as a “rotation in office” that would “perpetuate our liberty” — but if done too quickly, or if too many people leave at once, losing Cabinet members can be costly. In 1979, TIME described the purge of five of President Jimmy Carter’s Cabinet members in 72 hours as “amateur melodrama.” His Vice President Walter Mondale recently told TIME that he regretted those purges because they “gave the impression that we were falling apart, and we had to work doubly hard in the next years to demonstrate to the American people that we were on top of the White House.”

Certain Executive Branch jobs are particularly troublesome to lose, because turnover in those roles tends to make the President look bad. Secretary of State, Secretary of Defense and Attorney General, “are the most important Cabinet positions that presidents would be reluctant to throw somebody out of,” says James Pfiffner, a professor at the Schar School of Policy and Government at George Mason University. “It makes them look like they’re in disarray or that they made the wrong choice, so they try to ease people out or paper over it.”

These days, however, the shifting role of the president’s advisers may be changing the calculus about staff turnover. Specifically, individual Cabinet members have generally become less influential, so an individual departure can be less of a crisis — but, at the same time, there’s more opportunity than ever for conflict to arise.

While the Cabinet has always been a sounding board for the President, it used to be a sounding board that could speak for Congress. Though Lincoln was unusual in picking his own rivals for his Cabinet, it wasn’t uncommon for the group to include people who, while from the same political party, disagreed on details. That meant, says Russell Riley, Professor and Co-Chair of the Presidential Oral History Program at the University of Virginia’s Miller Center of Public Affairs, that different congressional factions of that party could find allies within the group.

“Because the executive departments are created by Congress, and because the departments rely on Congress for funding, this meant that [for the nation’s first 150 years] the Congress tended to have greater influence on presidential behavior, indirectly,” says Riley, who spoke to TIME as part of a presidential-history partnership between TIME History and the Miller Center. “Members of Congress could count on having some friendly voices who would try to influence the president on their behalf.”

However, during Franklin Delano Roosevelt’s administration, when New Deal economic recovery programs and World War II spurred the creation of so many federal agencies that the executive branch had to be reorganized, the population of the White House changed. Whereas the President’s personal staff had once comprised a few clerks, it soon grew to include a large number of new staffers who filled some of the roles that had previously been performed by Cabinet secretaries. These new staffers, and the influence they wielded over the president, were further from Congressional influence.

Nixon expanded the White House Staff even more, Pfiffner adds, especially growing the staff for National Security Advisor Henry Kissinger. Meanwhile, his adviser John Ehrlichman recruited domestic policy experts to join the policy team at the White House; as a result, programs that might otherwise have been created at agencies were crafted at the White House instead, such as Daniel Patrick Moynihan’s Family Assistance Plan. “Nixon was much more conservative than his Cabinet members,” Pfiffner says, “[Nixon’s Chief of Staff] H.R. Haldeman and Ehrlichman would be telling him, look these guys are not on board for your re-election. They’re not being as tough as we want them to be. So Nixon created a parallel bureaucracy in the White House.”

In rare cases, First Ladies have gotten involved in staffing decisions. Last month, a deputy national security adviser was redistributed from the White House after Melania Trump put out a statement declaring that she “no longer deserves the honor of serving in this White House.” Decades earlier, Nancy Reagan had urged Ronald Reagan to fire his Chief of Staff, Don Regan, who later said that he didn’t get along with her because she would repeatedly ask him to fire people and to schedule her husband’s appointments based on horoscopes, per his 1988 tell-all.

In some ways, dust-ups and disagreement within any group of advisers are inevitable — but the more the Executive Branch has grown, the more those disputes can take center stage. What’s going on in the Trump White House is not exception. After all, as Elizabeth Sanders, professor of Government at Cornell University, puts it, there’s “plenty of room to muck up.”