Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof...
That depends how you define "separation of church and state". If you mean public funds can't be used to advocate particular religious beliefs, then yes. If you mean that people aren't allowed to advocate their own religious beliefs in a public forum, then the principle goes blatantly against what the Constitution says. Both halves of the clause need to be respected.
If a school teacher places the 10 commandments on the wall... congress has made no law respecting an establishment of religion
If the congress or the courts (by legislating from the bench) declare that a teacher can't place the 10 commandments on the wall.. then the government has prohibited the free exercise thereof.
seems pretty cut and dry to me
only a liberal with an agenda could see it otherwise.