I am an atheist, which firmly puts me out of the "social conservative" circle.
But I am an adherent to Constitutional authority as any fundamentalist. Human actions are, by definition, based upon physics. What choices we make are not constrained by a religious edict or a socialist edict. Yes, I can play the "indoctrination comparison" game myself.
I don't doubt that the country was founded on freedom of religion. If Jews, conservatives, Muslims, and Buddhists can be equally "socially conservative," why should atheists be considered any less conservative?
I do get your point, though. Structure of peaceful human conduct MUST be taught. What cannot be tolerated is the assignment of actions based upon religious (or lack of) adherence.