Lord Acton covered this well in his oft repeated quote: "Power tends to corrupt, and absolute power corrupts absolutely. Great men are almost always bad men." That covers the Alexanders and Caesars of the past, and the Left, Right, and everything in-between of today. We will always have tyrants as long as half the people support Right wing tyrants, and half support Left wing ones. Abraham Lincoln was considered a tyrant by many Americans in his day, only to be lionized and deified later. Same with FDR. Reagan has been sanitized by the historians, just as George W. Bush, the butcher of Iraq has been. They're all monsters. Partisan politics feeds them.