It's an outdated question. I can't imagine that anyone who follows today's news can entertain the fantasy that the president is the most powerful person in the world. That's a worn out trope that the media finds convenient but doesn't stand up to reality. Do you really think that a dictator in China, who is not subject to American checks and balances, is less powerful than our president? Maybe we, as a country, as still slightly more powerful than them, but it's not all vested in our president. Even beyond what is built into our system, the president's power has greatly eroded over the years. Our bureaucracy can convene a secret court to surveill the president with false evidence, the other party can impeach on a whim, and the media can conduct endless smear campaigns with impunity. This is the situation whoever is president. It's only American hubris that has kept everyone from laughing at the idea that the president is the most powerful person in the world but that notion is well on its way to changing.
