"One person, one vote" is a desirable property of voting systems. It entails that, for single-winner elections (like President, in the case of the US), the candidate with the most votes wins, and for multi-winner ones like Congress the party with the most votes gets the most seats.

Neither of these things are currently true for the US, with voters having wildly unequal voting power, with the consequence that these conditions often fail to be met for specific elections like the Presidency in 2016.

As long as it remains possible for the winner of the election to lose and the loser to win, this question will by default resolve to NO; changes enacting one person, one vote need to be the law of the land for this to resolve YES.

This market applies to nationwide elections in the USA; if the country ceases to exist without a clear successor, this resolves N/A. Either the Most Powerful House of the legislature or the Least Powerful one being elected by one-person-one-vote is enough to resolve YES.

Winners are not required to have a majority, only a plurality; I reserve the right to resolve as N/A if a method is adopted that forces an apparent majority even when no candidate is really supported by a majority of the people, like the method currently in use in Maine and Alaska (IRV).