Unfortunately I live in a country in which due the fact that over 90% of the population is not just Catholic it's is Roman Catholic and the Church has quite some power in state maters even if, legally, it should have no such thing (for example in most elementary schools only Roman Catholic religious education is provided as part of regular school classes). The region in which I live particularly is tricky since it has the smallest percent of Roman Catholics in the whole country - only around 70% - making the national policy towards the Church quite not-supported.

In some countries the secularization of Religion and State is next to complete. In some states Religion is even considered an enemy and an strong activity for atheism is present (ex and current Communistic states are well known for this). Naturally in some countries religious institutions like the Church have a powerful influence.

[quote=So Boerd]
Better question, why should there be any particular insulation from religion? Hypothetically here in the US, a school could distribute Communist Manifestos but not have a moment of silence for prayer. What exactly is the practical difference?
[/quote]
Wikipeaia to the answer:
"Religion is a set of variously organized beliefs about the relationship between natural and supernatural aspects of reality, and the role of humans in this relationship."

"Political ideology is a certain ethical set of ideals, principles, doctrines, myths, or symbols of a social movement, institution, class, or large group that explains how society should work, and offers some political and cultural blueprint for a certain social order. A political ideology largely concerns itself with how to allocate power and to what ends it should be used."

AKA religion works with the supernatural, without any possible profs given while political ideologies try to come up with the best system to organized people and their success can be measured and studied with scientific methods (political & social sciences). So while most of religions work by hopping that their believers buy their dogmas about the supernatural political ideologies work by people agreeing to their system of social organization.