The display tent at the Reason Rally 2012 on March 24 smelled of wet rain gear and sweaters soggy from the near-constant drizzle. Atheists, freethinkers, and secularists of all stripes were checking out booths from two dozen or so atheist groups.

The crowd inched around the perimeter of the tent, but traffic stalled where people clustered for photos. Like carnival-goers with a muscleman cutout, they took turns standing behind an empty picture frame with, "This is what an atheist looks like" printed below.