Ok, YellowSnow...some good points there.
But there are other angles here to consider.
First, it is not against anything in the Constitution to prevent the mix of religious institutions and schools. In fact, it happens all the time without consequence. When I was in school we performed the Hallelujah Chorus. Prayers are said at graduations. Visiting churches as part of academic studies is NOT new nor condemned.
What is new is militant groups threatening lawsuits. What happens is that with the backing of the FFRF, of which this group in Arkansas is an off-shoot, they hire publicity hound lawyers to threaten lawsuits. It isn't the event that gets things cancelled it is the threat of costly defense of the events. The result is exactly the opposite of what the Society of Free Thinkers say they espouse -- that the beliefs of one is imposed on the others.
What gets lost in all this is that the school was not pursuing controversy in their field trip. They weren't pursuing religious study, which is their right and obligation to do under curriculum standards. They were pursuing the arts, which they are also required to do. Like all things associated with education, there are standards and review processes in place to see that what is used conforms with the stated curriculum. These things they passed.
This is event wasn't stopped because it was "right" to do so. It was stopped because it suddenly became a financial liability to the school district. And this because of a minority opinion.
Lost in the many facts of the episode was the glamor, once again, and the hype, of the Church vs. State argument. Oddly, it was the separation clause that was exactly exercised by imposing the will of "no-faith" on those of differing views.
I personally believe in keeping religious interpretation OUT of the schools. But you cannot escape the study of religion in history. It is vital. Students should be studying the origin of the Bible (even if most Christians knew the true origin of the Bible they would be shocked). Students should know about the Quran and other ancient scripture and the impact of belief systems on all societies. They study Greek mythology, paganism, ancient Native American beliefs and others. There's nothing wrong with that and everything appropriate to it.
In fact, I HOPE many schools over the course of this most current event took in the lessons of both religion and democracy. That is, after all, the purpose of education.
But keeping the school away from an artistic production held at a church (and one parents were allowed to opt out of, another fact conveniently not reported) was totally the wrong thing to do.
School children visits mosques and synagogues everyday. Do you hear complaints?