From Charles Krauthammer (1950-2018) via Fox News:
America is the only country ever founded on an idea. The only country that is not founded on race or even common history. It’s founded on an idea and the idea is liberty. That is probably the rarest phenomena in the political history of the world; this has never happened before. And not only has it happened, but it’s worked. We are the most flourishing, the most powerful, most influential country on Earth with this system, invented by the greatest political geniuses probably in human history.