That's false. We've had autocratic rule off and on in the US. Most US Presidents have shown self-restraint with that authority, usually during wartime. George Washington could have been king, and declined. Abe Lincoln had authoritarian powers, as did FDR. They both wielded the power (mostly) justly and set it aside without incident. There are other examples of benevolent dictators from history, for example Lee Kwan Yew of Singapore. In all cases there are valid points of criticism, but the net effect of their rule was positive. Hitler, Stalin, Pol Pot, Trump, Putin, Un, etc are cautionary tails, but that doesn't mean that authoritarian power is always used for self-gain.