Since George H. W. Bush’s death, many observers have noted that he embodied a less rancorous, less polarized political era. But underlying that civility was something deeper: Bush was the last person to occupy the Oval Office whose opponents saw him as a fully legitimate president.

That’s because in the contemporary United States, presidential legitimacy stems from three sources. The first source is democracy. Although America’s system of choosing presidents has many undemocratic features, many Americans associate presidential legitimacy with winning a majority of the vote. The second source is background. Throughout American history, America’s presidents have generally looked a certain way. They’ve been white, male, (mostly) Protestant, and often associated with legitimating institutions such as the military, elite universities, or previous high office. Americans are more likely to question the legitimacy of presidents who deviate from those traditions. The third source is behavioral. Presidents can lose legitimacy if they violate established norms of personal or professional conduct.

George H. W. Bush was the last president who could not be impugned on any of these fronts. He was elected with a clear majority of the popular vote. He was racially and culturally familiar: A wasp man who had served in World War II, attended Yale, and held a variety of top government jobs. And he behaved the way Americans expect their presidents to behave.

Since then, every president has faced some sort of crisis of legitimacy. Bill Clinton’s began with the fact that in 1992 (and again in 1996) he won only a plurality of the vote. Exacerbating that legitimacy gap was the fact that he had avoided service in Vietnam. Soon after Clinton took office, an Air Force general openly derided him for “draft dodging.” Senator Jesse Helms warned that if Clinton visited a military base in North Carolina, he’d “better have a bodyguard.” Already deemed culturally illegitimate by some on the political right, Clinton was then exposed as having violated norms of personal decency by having an affair with a White House intern—and impeached.

Then came George W. Bush, who in 2000 lost the popular vote and entered the White House after a bitterly partisan, 5–4 vote on the Supreme Court. Next was Barack Obama, an African American with a Muslim middle name whose father hailed from Kenya and who grew up partly in Indonesia. For many Americans, Obama’s presidency was racially illegitimate. As late as 2016, only a quarter of Republicans conceded that he was born in the United States. Now we have Donald Trump, who lost the popular vote in an election in which he received help from the Russian government, and virtually every day comports himself in ways that many Americans deem unpresidential. According to exit pollsconducted during last month’s midterm elections, more than three-quarters of Democrats want Trump impeached.  

What explains this crisis of presidential legitimacy since Bush? Partly, it’s because he was the last president to fight in World War II, which brought Americans of all classes and ideologies together in common purpose. Clinton, by contrast, came of age during Vietnam. Like many students at elite universities, he avoided service in that enormously divisive war—and after becoming president endured a fierce backlash for doing so.

George H. W. Bush was also the last president whose private life was not intensively scrutinized by the press. The watershed was 1987, when likely Democratic front-runner Gary Hart left the presidential race after the Miami Herald published a story suggesting an extramarital affair; shortly after he quit the race, the National Enquirer ran a photo of a woman who was not his wife sitting on his lap on a yacht called Monkey Business. That cultural shift came too late to engulf Bush: He wasn’t asked about rumors that he had had an extramarital affair until near the end of his first term, and when he angrily denied the charge, the press mostly dropped the subject. Clinton, by contrast, was dogged by accusations of infidelity from virtually the moment he announced his presidential candidacy until Newsweek’s Michael Isikoff brokethe news of his affair with Monica Lewinsky in January 1998, which set off a chain reaction that led to Clinton’s impeachment.

But the single biggest reason for the post-Bush legitimacy crisis involves the relationship between democracy and race. Bush was the last white president who entered the White House after winning a majority of the popular vote.

That meant Bush enjoyed both uncontested democratic legitimacy and the racial legitimacy that comes from being white in a country in which whiteness and political power have long gone together. Bush won the presidency in 1988 by overwhelmingly winning the white vote, something he achieved in part by linking Michael Dukakis to the specter of black crime. And in 1988—when whites comprised 85 percent of the American electorate—overwhelmingly winning the white vote was enough to ensure a popular majority.

Since then, the white share of the electorate has steadily declined. By 2000, it was down to 81 percent. That decline played a crucial role in George W. Bush’s failure to win the popular vote, which undermined his legitimacy. By 2008, the white percentage had dropped to 74 percent, which helped Obama defeat John McCain. But while winning the popular vote gave Obama democratic legitimacy, his blackness undermined his racial legitimacy in the eyes of many conservative whites. In 2016, the white percentage of the electorate fell to 70 percent—too low for Trump to win the popular vote, despite winning a large majority of white voters, a failure that has contributed to his own legitimacy crisis.

Race is crucial to any comparison of George H. W. Bush to the presidents who have succeeded him. Yes, Bush was a personally decent man who respected the norms of his office. But so was Obama. It wasn’t only Bush’s personal respectability that made his presidency less rancorous. It was his racial respectability, the fact that he personified a racial hierarchy that has since been unsettled by demographic change. Since Bush, two forms of presidential legitimacy—democratic and racial—have diverged. One group of Americans has spent the last two decades seething about white presidents who didn’t win the popular vote. Another has spent the last decade seething about a black president whose very Americanism they did not accept.

Why are voter fraud and voter suppression bigger topics today than when Bush was president? Because it has become harder for white Americans to elect presidents unless they either keep people of color from voting or reject their votes as illegitimate. In 2020, the white share of the American electorate is predicted to drop to 67 percent. That, more than any other single factor, is why America is unlikely to elect a president who enjoys the same uncontested legitimacy as George H. W. Bush anytime soon.