Your point(s) is well taken.  However, please do not forget that by our Constitution, there are a number of built-in safeguards against a dictatorship.  And no one "wrongly elected" POTUS could do what you fear.  They would have to have the entire congress, the Supreme Court, and the military behind them, not to mention the vast majority of the citizenry.  That is why it could not happen in the US.