Ronald Reagan was a terrible politician, but he absolutely nailed this quote:

Perhaps you and I have lived too long with this miracle to properly be appreciative. Freedom is a fragile thing and it’s never more than one generation away from extinction. It is not ours by way of inheritance; it must be fought for and defended constantly by each generation, for it comes only once to a people. And those in world history who have known freedom and then lost it have never known it again.