"A republic, if you can keep it" is actually attributed to Ben Franklin.

All this posturing about "I'm going to register as a Muslim!" is really very silly. The proposal is to revive a Bush-era registry for non-citizens from countries with government-sponsored terrorist organizations. If a US citizen tried to register as some kind of political-theatrical performance of self-congratulatory faux-solidarity, the DoHS will just see in the database that it's a citizen and laugh at her.