Most philosophers agree "one person, one vote" is the right policy in a democracy.
But who counts as a person?
You could say any individual affected by the government should count. But it's hard to say who is and who's not affected by the government. And would you let children vote? Probably not.
That answer's clearly wrong.
You could also say any adult citizen should count. But would you let POWs, felons, tourists, aliens, and the mentally incompetent vote? Probably not.
That answer's also wrong.
I'd go out on a limb and say any democratically competent adult should count. And I'd determine whether any adult were "democratically competent" by requiring her to answer, in writing, two questions:
You might say, "Wait, the Founding Fathers rejected epistocracy!"
That's true; and they also rejected the Ancient Greeks' democracy, in favor of the Ancient Romans' republicanism.
Under the Founding Fathers' preferred system, citizens can vote to elect politicians, who act as a firewall against mob-rule. They defined a citizen as any wealthy white man.
But 230 years later, we have a democracy, the political system Plato called the "agreeable form of anarchy." We let nearly any yahoo vote.
Plato also warned: Democracies inevitably give rise to tyrannies when a populist autocrat can play to the mob's passions.
It's time for an overhaul—before we're led over the cliff.