My Saturday began on the West lawn of Capitol Hill, where conservative activists were mounting one final, desperate effort to block health care reform. They came by the thousands, carrying flags and pushing strollers, in a demonstration of genuine grassroots fervor. They chanted “Kill the Bill,” over and over again, in a vaguely menacing tone that, perhaps, foretold a bit of ugliness to come.

But the most remarkable thing about the demonstration was how little it had to do with health care. The signs said “Stop socialism,” “A government of laws, not men,” “Respect our constitution--preserve our republic.” Nobody talked about death panels. Instead, one speaker--a Chicago radio host, I believe--attacked the First Lady’s obesity...