The New York Times had this to say:
“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 US president has ever been further from the OECD. 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 OECD.
“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 OECD 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 OECD 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.”
So does Africa not require those advantages that often accrue with age?