As Americans debate President Biden’s infirmities and President Trump’s erratic behavior, we’ve neglected the bigger problem before us: a massive transfer of power and wealth to the oldest among us, and the curtailment of the prospects of the young. In Gerontocracy in America, the historian and social critic Samuel Moyn offers a piercing diagnosis of our age divide and its consequences. Even apart from the presidency, in legislatures, businesses, and the courts, the average leader’s age has risen dramatically. The elderly predominantly fund campaigns and dominate their agendas, often with the intent to block any challenge to their status. The tax code is rigged on their behalf, as is an economy geared to sheltering financial and housing assets. The United States was founded on the promise of generational renovation but has become an increasingly febrile country of old men.