Faced with the unraveling of his presidency, Richard M. Nixon could not fathom how it had all happened. “You look at Watergate and all that was involved,” he groused to Vice President Spiro Agnew. “What was it? A crappy little thing. There’s nothing there — they didn’t get anything. It hurt us in the election. We would’ve got three or four percent more. What in the name of good God is this all about?”

The reader might wonder the same thing, encountering journalist Garrett M. Graff’s doorstopper of a Watergate book. It’s all there: the pantheon of Nixon administration characters, from John Mitchell to G. Gordon Liddy to John Dean; the Cuban burglars and the Nixonian paranoia. And yet at the end of the book, what remains is as much a mystery as ever. “We’ll never really know the full truth of Watergate,” Graff concludes.

This is not for lack of research. Watergate: A New History offers an exceptionally detailed account of the Watergate saga, and an important revisionist one in certain key ways. Most notably, Graff downplays the investigative journalism of Washington Post reporters Bob Woodward and Carl Bernstein — immortalized in the 1976 movie All the President’s Men starring Robert Redford and Dustin Hoffman — noting that many other newspapers were onto the Watergate story at the same time.

Taking into full account the identity of Woodward’s clandestine whistleblower “Deep Throat” — Mark Felt, a career FBI employee who was angry about being passed over for the top spot after Bureau chief J. Edgar Hoover died — Graff follows historians such as Beverly Gage in portraying the Watergate leaks as the inevitable result of office politics at the FBI, which Nixon had tried to push to do more wiretapping than even Hoover could abide. (One nice twist Graff highlights is that for all the years of speculation about who Woodward’s source could be, Nixon was pretty sure right away that it was Felt.)

In Graff’s account, the botched Watergate break-in on June 17, 1972 — in which five people connected to Nixon’s reelection campaign burgled the Democratic National Committee’s Washington DC headquarters in the Watergate Office Building — appears as just one of Nixon’s many sins. From selling his vice-presidential papers before his presidency to taking a tax write-off (the actual transgression that led to Nixon’s famous plea, “I am not a crook”) to the “Chennault Affair” (in which Nixon’s 1968 campaign sabotaged Vietnam War peace talks with the promise that if he won he would be more pro–South Vietnam) to the break-in at Pentagon Papers whistleblower Daniel Ellsberg’s psychiatrist’s office to illegal corporate campaign contributions, Graff’s book makes clear just how deep the rot ran. At one point during the 1972 election, Nixon’s associates were running various schemes to disrupt opposing campaigns, including getting fake volunteers to mix up the scripts for phone calls or persuading campaign workers to go out drinking rather than hand out leaflets.

In his footnotes, Graff suggests that despite the many Watergate memoirs and thousands of hours of tape, it’s impossible to know everything the Nixon administration did, was doing, or tried to do. Observing that one of the Watergate burglars seems to have dialed the phone number of the Chilean embassy to ask for a visa, Graff muses, “There’s an odd thread of Watergate that seems often, to return to Chile, across the burglars, ITT, and other parts of the scandal, perhaps hinting at deeper connections or further, still-uncovered plots and geopolitical intrigue.” Like any good conspiracy theory, there are always more threads to follow. We’ll never know what Nixon and his chief of staff, H. R. Haldeman, said on those eighteen and a half minutes of blank tape three days after the June 18 break-in.

But why did it all happen? And what is the model of power and justice that this sprawling, interlocking, and mysterious scandal came to embody?

Watergate bequeathed to us a particular model of power and manipulation, one where small groups of influential people acting together to subvert the rule of law can be brought to justice — in which no one, not even the president, is above the law, and in which intrepid journalists and brave congressional representatives and dogged investigators can reveal the truth and put the demons away.

Hovering around the edges of Graff’s account is another vision. In this one, Watergate happened because of a particular political moment. Nixon’s exaggerated anxiety was a product of the Cold War, of the memory of McCarthyite repression of the Left. In the throes of Vietnam, facing a world that had become increasingly impossible for the United States to control and a domestic political scene that was at times literally explosive, he sought to repeat what he knew: using government power to bring the Left to heel.

The problem for Nixon was that the political crisis of the late 1960s and early 1970s had gotten out of hand. It wasn’t just the Pentagon Papers or Daniel Ellsberg — it was the Vietnam War, the massive marches, the crumbling of a Cold War order. The more he sought to instantiate and revive an anti-communist consensus — and Graff makes clear that Nixon was obsessed with the commies right up to the end — the more the movement he tried to subdue pushed back. No longer could Nixon simply call out the FBI to preserve national security, or the authority of the presidency, in the face of left-wing challenges; in the end, that authority had been undermined already, and Watergate was the result as much as the cause.

Scholars in recent years have suggested that Watergate’s real importance is its role in dismantling postwar liberalism. It undid Nixon, yes, but it also managed to topple the authority of the government itself, opening the way for Ronald Reagan’s anti–New Deal vision of unimpeachable markets, businessmen, and executives, while also providing fodder for conservative activists who believed that Nixon had been victimized by liberal mobs.

But the era of Donald Trump suggests another possibility. Watergate’s significance may be that it gave us a particular model of government malfeasance, while obscuring the broader political context that made the revelations of the time radical. After all, just as the political challenges of the early 1970s were what stimulated Nixon’s various machinations that led to his undoing, they also helped spark the reaction and made it impossible for him to continue on as chief executive.

Graff’s book shows how long Nixon had been mulling his own departure, a sign that he knew perfectly well how weak he was politically. At some point in the spring of 1973, more than a year before he resigned, Nixon burst out to Henry Kissinger: “Maybe we’ll consider the possibility of, frankly, just throwing myself upon the sword and let Agnew take it. What the hell?” Later that year, he mumbled to his chief of staff Alexander Haig: “Wouldn’t it really be better for the country to, you know, just check out?”

Today, the political dynamics are fundamentally different, and this is why the congressional investigations of Trump have thus far gone nowhere. Not only has the central drama of impeachment already happened (twice!) — the investigations have not revealed anything fundamentally unknown. There’s no mystery to be exposed: we all knew at the outset that Trump refused to accept the election results, that he called a massive crowd together, and that he egged it on toward the Capitol. The hearings added detail, but not much more. And crucially, there is a large part of the US public that still sees Trump as on their side — there is no mass political movement that rejects the larger commitments of the society, as there was by the late years of the Vietnam War. Without the latter, there are real limits to what all the congressional investigations in the world can achieve.

But who knows? We can always hope — maybe someone will someday turn over the tapes.