Would you agree that people overestimate the power of the President of the United States?

Yes and no. There are things the POTUS gets the credit/blame for that are beyond his ability to change, and other things in which he can exert the tremendous power of his office.

Most of the time they do... but then again there are folks who try to Take too mush and Push their power Limits too far Like the current occupant of the White House and the One who was defeated...

I would say yes because they do not understand how government works.