First off I want to say that I do not believe the US President is the most the powerful person in the world. If he was, his actions would actually make a difference, for good or for bad. Instead, he flip flops and does not do anything significantly different than the previous presidents. Those that did ok before Trump mostly continue to do ok. Those that were suffering before Trump continue suffering with Trump. If something catastrophic happens in the next 2 years, it would almost certainly still happen under a different president.
The political system is designed to follow a fixed pattern. Choice is just a mere illusion.
I think Stan Lee is more powerful than Trump. His Marvel Universe has touched the world.