Separation of Atheist and State

We're all over separation of Church and State. It's a principle widely recognized in multiple countries, and we all see the unfortunate effects of failing to maintain that separation. But it occurred to me...should there be a separation of atheism and the State?

This gets tricky. The principle is that there should be a separation of the State from the Church, but not that there should be a separation between public service and religiosity or spirituality. Indeed, many feel there's a necessary link between strong spiritual values and being a good public servant. We draw the line, though, at using the power of the State to support any particular Church, or using the doctrine of any particular Church at informing public policy.

See? It gets interesting. I doubt any atheist would argue that the power of the State should be used to support atheism in any form. But what about using the principles of atheism to inform public policy? Should a State be organized on atheistic principles?

I think the answer lies more or less in  how we handle religion in the political sphere. Any given legislator is free to have his decisions underpinned, conditioned, influenced, by his personal beliefs, whether these are the beliefs of a religion or of atheism. Those in the judiciary are supposed to follow the Law, rather than any god or philosophy. With a legislator, the democratic assumption is that if the legislator belongs to a religion out of step with his constituency, and lets that influence too greatly influence his legislating, then the people vote him out. That can't happen with a judge. The executive is trickier, as only a handful of executives are elected.

In any event, the thought does bother me a bit. It's all very well to say to keep religion out of politics, but logically that argument should extend to any philosophy, and that doesn't feel right either. Separation of Existentialism and State?