The American presidency is starting to feel like a gerontocracy.
Donald Trump, who turned 74 in June, entered office as the oldest president ever inaugurated. If he wins re-election and completes a second term, he will become the oldest American to leave the presidency as well.
If November instead favors Joe Biden, the presumptive Democratic nominee, Mr. Biden will become the oldest-ever president at 78.
This looming septuagenarian slugfest has helped make America’s aging political leadership a campaign issue, with both candidates attacking the other’s health and mental fitness.
But what’s been largely overlooked in this domestic debate over age is how America’s graying presidency sets it apart from its peers. In many of the world’s longest-lasting democracies and most advanced economies, the age of elected leaders is falling, not rising. And while Mr. Trump and Mr. Biden are unprecedentedly old in an American context, national leaders their age are also practically unheard of across the modern history of other major democracies.
Since 1950, the average age of heads of government in the three dozen member countries of the Organization for Economic Cooperation and Development has steadily declined, from above 60 years old to around 54 today. The average O.E.C.D. national leader is now two decades younger than Mr. Trump — and almost a quarter century younger than Mr. Biden.
American presidents have been out of step with other rich democracies before. And beyond the United States, Chile and Israel are also currently led by men over 70. But no U.S. president has ever been further from the O.E.C.D. average than Mr. Trump. If elected, Mr. Biden would further widen that gulf.
And it isn’t just the American presidency that’s gone gray. The average age of Congress has trended upward for decades. Nancy Pelosi, the House speaker, is 80; Mitch McConnell, the Senate majority leader, is 78. The Supreme Court’s nine justices average above 67. Mr. Trump’s cabinet averages over 60, among the oldest in the O.E.C.D.
What explains America’s aging leadership? A tidy, all-encompassing answer is unlikely, but experts offered three theories.
Demographics suggest one possible explanation. Many older leaders belong to the Baby Boom generation, comprising Americans born between 1946 and 1964. For several years after World War II, American boomers dwarfed contemporary generations in other countries.
“The 1950s was an extraordinary decade because the rest of the world was a mess, and we were fat and happy and producing babies like nobody’s business,” said Elaine Kamarck of the Brookings Institution. Sheer numbers, coupled with the country’s midcentury economic prosperity, could have better positioned more Boomers to win and hold office, raising the age of American politicians over time.
Older Americans’ political power could also stem from how generations interact. Boomers were more politically engaged than the Silent Generation before them and Generation X that followed, radically transforming society, voting at higher rates and producing the last four presidents (if elected, Mr. Biden would become the Silent Generation’s first).
That “dominant-recessive” generational pattern isn’t found in most other O.E.C.D. countries, said the demographer Neil Howe. The lack of a dominant postwar generation in those countries could have created space for younger political leaders to take power.
The way countries select their leaders offers a third possibility. In most O.E.C.D. countries, the head of government is a prime minister chosen by fellow lawmakers in the national legislature. Because party members pick their leaders, and can recall them at will, parliamentary systems give political parties significant control over whom to elevate, said Kaare Strom, a political scientist at the University of California, San Diego. And parties often have strategic reasons to pick younger leaders: to appeal to particular constituencies or to brand themselves behind more telegenic faces.
Presidential systems, by contrast, give parties less control over who from their ranks will run — and which candidate voters will prefer. “The process is more driven by who’s out there, who’s interested, and what kind of resources they have,” said Professor Strom. “There’s not the same kind of institutional control and vetting of those candidates that you have in the European parliamentary systems.”
Particularly in the United States, he added, national contests can favor candidates with large reserves of personal wealth, like Mr. Trump, or those with long records of public service and national exposure, like Mr. Biden — advantages that often accrue with age.
The data provide some evidence for these three theories. The steady decline in O.E.C.D. leader age has been largely driven by European countries that experienced smaller baby booms and by countries with parliamentary systems of government.
Origins aside, how much does gerontocracy matter? Emphasizing older politicians’ age, or urging their replacement, can smack of ageism. Nevertheless, their dominance can produce stagnation. In Italy and Japan, Professor Strom said, successive older leaders in the 20th century contributed to periods of political and economic sclerosis.
The critical question may instead be whether a country’s politics still permit younger leaders to rise and, ultimately, take their elders’ place. Even in the United States, that seems to remain the case. America’s reigning septuagenarians haven’t prevented fresh faces — Democrats like Pete Buttigieg and Alexandria Ocasio-Cortez and Republicans like Tom Cotton and Josh Hawley — from emerging.
These younger heirs apparent suggest American gerontocracy won’t last forever. The ascension of younger leaders in the United States may ultimately bring the country more in line with several O.E.C.D. peers. Prime Ministers Sanna Marin of Finland, Jacinda Ardern of New Zealand and Justin Trudeau of Canada, among others, assumed the top job in their 30s or 40s.
Millennials, another large generation Mr. Howe believes is rapidly reshaping American politics, seem especially well positioned to replace the country’s stable of aging leaders. They may also eventually replicate it. Today, older generations are ascendant. But as Ms. Kamarck predicted, “in 30 years they’re going to be talking about these damn millennials, hanging around too long, dominating our politics.”