The danger comes from left and right, both of which aspire to have a body of elders impose narrow cultural and moral norms on everyone, overriding our right to think for ourselves. (Progressives and National Conservatives have a lot in common in that regard, even if they differ on what is to be imposed.)

This point about the fragility of liberty was well understood by the Irish politician, judge, and orator John Philpot Curran (1750-1817), who said: "The condition upon which God hath given liberty to man is eternal vigilance; which condition if he break, servitude is at once the consequence of his crime and the punishment of his guilt."

As often happens, variations of this insight have been attributed to other people, most famously Thomas Jefferson, who is widely and apparently erroneously thought to have said more pithily: "The price of liberty is eternal vigilance." Curran has missed out on the credit he deserves.

At any rate, we have a problem. Although liberty is never safe from political ambition or even good intentions, most people are understandably absorbed in raising their families, earning their livelihoods, and just plain living. Thinking about liberty, much less exercising vigilance, has a low priority — if it is on their agendas at all. I'm not finding fault; it's just a fact.