Benjamin Franklin’s observation to a woman that the United States was “a republic, if you can keep it” has become so ubiquitous that its original foreboding tone has almost been lost entirely. The phrase in our own day has become almost a cheerful maternal admonition. Yet, the Revolutionary generation that wrote the United States Constitution and shaped the American republic’s regime treated the phrase not so much as a kindly or triumphalist admonition, but as a threat with consequences that were near at hand.