I think it'd be 6-3 the other way. The removal of religion from schools has been one the biggest points of contention on the right-wing. It's probably second only to their attack on abortion rights. I think this is far more insidious though, as the plain text of the Constitution is clear as to religion.
The Establishment Clause is one of the only clauses in the Bill of Rights whose plain text actually goes a bit further than what even most social liberals want, or at least want to make a federal case out of right now. Special cases like cross-shaped monuments that are now of historical value themselves aside, a rigorous Establishment Clause analysis of things like "In God We Trust" and the expressly theistic version of the Pledge of Allegiance probably junks those things even though doing so is not currently very high on the socially liberal/SECULAR wish list.
