The passage of time can do wonders for historical memory, especially when it comes to politics. Consider the reputational evolution of three American presidents: Ulysses S. Grant, Dwight Eisenhower, and Ronald Reagan. Grant departed the WhFDRite House in 1877. For pretty much the entire 20th century, the received wisdom held that his administration was a corrupt failure. Today, we are awash in books extolling Grant’s hitherto underappreciated greatness. Eisenhower’s rehabilitation did not take quite so long. In 1962, the year after he left office, one survey of scholars ranked him in the bottom half of American presidents. Yet by the early 1980s, pro-Ike revisionism had begun to take off, thanks in large part to the late Princeton political scientist Fred Greenstein and his 1982 book The Hidden-Hand Presidency. In a 2017 C-SPAN poll, historians ranked Eisenhower the fifth-best president ever, behind only Lincoln, Washington, and the two Roosevelts.

As for Reagan, his reputation has improved enormously since 1989 — almost too much. Along with Eisenhower and Harry Truman, he was clearly one of the three most successful presidents of the post-war era. But the Gipper has become a borderline mythical figure for members of both parties. To hear Democrats praise Reagan, and lament how far the GOP has strayed from his legacy, you would never know how viciously Democrats attacked him during his presidency. Likewise, to hear Republicans wax rhapsodic about their ideological hero, you would never know how often Reagan violated conservative orthodoxy, or how often the Right questioned his policies. Nor would you know just how fiercely Reagan-administration officials bickered among themselves.

That last point is one of the many useful reminders that Tevi Troy delivers in his new book, Fight House. A detailed overview of White House rivalries from the Truman administration through the Trump administration, the book provides a healthy perspective on some of our current political controversies.

For example, if you think the Trump White House is disorderly, combative, and filled with people who hate one another, you are of course correct. But those conditions have been the rule rather than the exception in modern presidencies.

As Troy explains, the size of the contemporary White House staff traces its roots back to FDR. Prior to the 1930s, presidents had a relatively small staff, relying mainly on their cabinet secretaries to do the heavy policy lifting. The New Deal changed everything. Its scope and ambition required not merely an expansion of government but an expansion of executive power in particular.

In 1937, the Roosevelt-appointed Brownlow Committee on Administrative Management issued a report arguing that “the President’s administrative equipment is far less developed than his responsibilities.” More succinctly, “the President needs help.” This led Congress to create the Executive Office of the President (EOP) in 1939.

“The EOP comprised a new White House Office, as well as the existing Bureau of the Budget, which had been lodged in the Treasury Department,” writes Troy. “The famous four words of the Brownlow Committee had set in motion a decades-long expansion, leading to the current White House operation of more than 1,600 people and the creation of the modern White House staff.”

How much do all those people and their various rivalries actually matter? That depends on the man in the Oval Office. Troy, a presidential historian who served in the Bush 43 administration, lists three key factors that both cause White House infighting and determine its significance: ideology, process, and presidential tolerance of turmoil.

Ideology can generate sharp disagreements, but it also can serve as the glue that binds together an otherwise fractious administration. This was certainly true under Reagan. In her 1990 memoir What I Saw at the Revolution, Peggy Noonan recounts a conversation she had with then–White House staff secretary Dick Darman when she joined the Reagan speechwriting team in the mid 1980s: “I’m sure you’ve heard all about this White House,” Darman said. “That there’s a great deal of infighting, and we’re split into separate warring groups which leak unpleasant things about each other to the amusement and delight of the media, which are not slow in passing it on.”

Darman then added: “It’s all true of course.”

And yet, despite the chronic infighting and leaking, Reagan achieved historic, world-changing victories on the economy and in foreign affairs. Today, these achievements easily eclipse memories of White House feuds.

Troy argues that ideology played a crucial role in helping the Reagan administration overcome its internal disputes and advance a coherent agenda. “Reagan’s well-defined conservatism meant that even aides who had no contact with Reagan had a keen sense of what he wanted and where he wanted the administration to go.” Thus, even when Reagan deviated from his ideology — as he frequently did — White House officials understood their strategic direction.

This gets to an important difference between Reagan and Trump (one of many, to be sure): Because Trump lacks any firm ideological grounding, and because he sends disparate signals even on core issues such as immigration, his administration has struggled to formulate consistent policies. Trump has certainly not helped matters with his disregard for process, his misguided personnel decisions, and his encouragement of conflict among staffers. Those who wish to paint the 45th president as uniquely erratic, and his White House as uniquely inept, can make a strong case.

Still, as Troy shows, we should not understate the ferocity of past White House battles or the dysfunction of past administrations. In 1948, during an Oval Office meeting with President Truman, White House special counsel Clark Clifford and Secretary of State George Marshall debated whether the U.S. should recognize the State of Israel. Marshall was so incensed by Clifford’s pro-Israel presentation that he never spoke to him again, nor did he even mention his name.

During the Kennedy administration, the animosity between Vice President Lyndon Johnson and Attorney General Robert Kennedy produced one of the most well-known feuds in American political history. This feud only escalated when Johnson became president following JFK’s assassination in 1963.

A few years later, during Richard Nixon’s full term, Henry Kissinger, then serving as national-security adviser, repeatedly clashed with Secretary of State William Rogers. At times, Kissinger’s treatment of Rogers and other Nixon officials was genuinely outrageous. Nixon himself grumbled about it to his first White House chief of staff, Bob Haldeman: “Goddamn it, Bob, he’s psychopathic about trying to screw Rogers.”

Nixon’s successor, Gerald Ford, was an accidental president who spent a tumultuous 29 months in office. “Staff rivalries and internal strife kept the Ford White House off balance throughout its short, rocky tenure,” notes Troy. This led to the so-called Halloween Massacre of late 1975, in which Ford changed his secretary of defense, national-security adviser, CIA director, and chief of staff, while his vice president, liberal Republican Nelson Rockefeller, announced he would not be on the ticket in 1976.

“Ford was a decent man, and a better president than he was judged at the time,” writes Troy. However, he “presided over a toxic White House staff that he ultimately could not control.”

Speaking of “toxic,” that would be one way to describe the relationship between Jimmy Carter’s national-security adviser, Zbigniew Brzezinski, and his first secretary of state, Cyrus Vance. The two men “disagreed on virtually every key issue that came their way: on the Soviets, on Iran policy, on China, and even on the national security process.” Their mutual hostility, combined with Carter’s indecisiveness and shortcomings as a manager, plunged the administration into “ineffectuality and constant fighting.”

With all that (and more) in mind, Troy takes a measured view of the Trump administration’s often circus-like atmosphere: “While the Trump White House is indeed replete with wild energy and rivalries, it is hard to say from the perspective of the past seventy-five years that any of the current rivalries are worse or more intense than Kissinger-Rogers under Nixon or Vance-Brzezinski under Carter.”

If Fight House has an overarching theme, it is the indispensability of presidential leadership, which is more art than science. White House rivalries can either help or hurt an administration — it all depends on how the president handles them. To adapt the old Potter Stewart quote, leadership is a bit like hard-core pornography: You may not be able to define it concisely, but you know it when you see it.