Just four presidents have faced impeachment charges in U.S. history—Andrew Johnson in 1868 surrounding the firing of a cabinet member; Richard M. Nixon in 1973 for his Watergate cover-up; Bill Clinton, in 1998-99 for charges of perjury and obstruction in the Monica Lewinsky scandal; and Donald Trump in 2019, for obstruction of congress and abuse of power, and again in 2021, for incitement of insurrection. Johnson, Clinton and Trump remained in office, while Nixon resigned in disgrace.

So, why was Watergate the only scandal to lead to the resignation of a sitting president?

Johnson aside, the time and place in history of the Nixon and Clinton presidencies are important to consider, says Lara Brown, director and assistant professor of the Graduate School of Political Management at George Washington University.

“One of the important realities of our history is that Watergate came on the heels of the Vietnam War,” she says. “The difficulty of the war—the large loss of life combined with the sense that there was no way to win—and the release of the Pentagon Papers—in which many in the public realized they had been ‘lied to’ about the war—contributed to the decline of trust in government which had begun in the latter half of the 1960s and it is evident in the polling.”

During Clinton's presidency, unlike Nixon's, Brown notes, trust in government was increasing.

“Some of this rise in trust was about the productivity of the working relationship between the Republicans in Congress and the Clinton White House,” she says. “In essence, people were pleased that legislation was passing and compromises were agreed to across the aisle, from balancing the budget to welfare reform.”

Plus, adds Brandon Rottinghaus, a political science professor at the University of Houston and host of the podcast, “Party Politics,” Watergate was the culmination of years of scandals and events.

“So, the outcome of the resignation of the president was surprising but not shocking,” he says.

Differences in economies also came into play, according to Brown, with the economy faltering in the early 1970s. “And when economic downturns happen, presidents typically take the blame,” she says. “Again, Clinton was on the other side of this trend—the economy was growing, not contracting.”

“The economy was a strong factor in the survival of Bill Clinton,” Rottinghaus adds. “With the U.S. economy booming, voters were reluctant to turn an incumbent president out of office. Party unity was another factor in the survival of Clinton. Nixon gradually lost the support of his Republican allies while Clinton maintained relatively strong support from his Democratic allies in Congress, even conservative members like Joe Lieberman.”

And, he adds, Clinton received bipartisan support for the handling of his job as president, “whereas years of Watergate had eroded President Nixon’s base of support to only core allies.”

Scott Basinger, an associate political science professor at the University of Houston, says the betrayal of Nixon’s allies contributed to his downfall, as well, while Clinton had fewer "co-conspirators," such as his secretary, Betty Currie. And, he adds, the type of scandal was also different—“personal immorality of a sexual nature rather than abuse of political power.”

“What is really fascinating to me is how public opinion changed during the year in which the Lewinsky scandal was the most prominent news story,” Basinger says. "Initially, Republicans and Democrats shared the opinion that if Bill Clinton had had sexual relations with Miss Lewinsky then he should be impeached. Where they really differed was in their assessments of whether Clinton had done what he was accused of.”

Over time, he says, Republicans and Democrats agreed Clinton had carried on an inappropriate sexual relationship with Lewinsky, “but their opinions about the reasonable punishment for that violation diverged.”

“Republicans thought that he should resign or be removed from office, and Democrats did not,” Basinger says. “This division also extended to assessments of the just punishment for Clinton perjuring himself and/or committing obstruction of government.” Democrats, Basinger says, were more willing to accept that lying about sex was less offensive.

Brown adds that the root of the Clinton scandal was an extramarital affair, which most people felt was a personal scandal and a private matter, not a political one.

“They resented Ken Starr for going far beyond his mandate, which was to investigate Clinton's involvement in the Whitewater real estate development,” she says. “Most saw the Paula Jones lawsuit and what was understood to be a consensual affair with Monica Lewinsky to be Clinton's personal problems.”

In today’s #MeToo environment, Brown says it seems unlikely that Clinton would have survived the vote in the Senate on his removal. “But at the time, the country had peace and prosperity and they felt that Clinton was doing a good job as president. They did not want to see him removed from office,” she says.

And while both men faced impeachment and lengthy investigations while in office—there was a large disparity in their approval ratings upon leaving office (66 percent for Clinton; 24 percent for Nixon).

“President Nixon’s approval and greatness rating improved slightly over time, but the stain of Watergate and his resignation will always be a ceiling to rise higher,” Rottinghaus says. “President Clinton gets credit for a strong economy and maintaining a peaceful world, so his legacy will always have room to rise. However, a reevaluation of the power imbalances involving personal sexual relationships in the context of the #MeToo movement will hurt Clinton’s overall rise in the rankings of great presidents.”

And, Brown adds, it’s important to note that, in general, expectations for the institution of the presidency and for the president as an individual were different in the early 1970s than they were in the late 1990s.

“People expected the presidency to be a lofty—above the people—kind of institution. Camelot, if you will,” she says. “And they expected the president to be ‘better than’—smarter, more trustworthy more moral (that the general public)—during Nixon's time in office than they did in the 1990s, when they wanted the presidency to be accessible and they wanted presidents to be more compassionate, relatable and authentic.”

Brown says Clinton's personal foibles also had already been on display during his campaign (Gennifer Flowers, draft dodging and marijuana experimentation, for example). “And so, people were surely less surprised by Clinton's scandal than Nixon's crassness and apparent meanness, which was revealed in the tapes of his private White House meetings, but he had not shown in public.”