Thesis: The executive branch is becoming too powerful.
Antithesis: If that ever happened, the white-collar desk jockeys at the IRS would rise in revolt against authoritarianism.
Synthesis: Democracies cannot be authoritarian as long as they pass the 
test.
The US can't become a dictatorship because USicans would only ever acknowledge that it's become a dictatorship if the president cancelled elections, and any would-be dictators know this and would choose any of the other dozens of ways to take control.