Have the courts stated that teaching evidence for creation would violate the separation of church and state?

NO. The U.S. Supreme Court has said just the opposite. A few evolutionist organizations, the ACLU, and many media outlets have propagated the myth that they have. The Supreme Court actually said that the scientific evidence for any theory of origins, including creation, has always been legal in the classroom. “Moreover, requiring the teaching of creation science with evolution does not give schoolteachers a flexibility that they did not already possess to supplant the present science curriculum with the presentation of theories, besides evolution, about the origin of life.”

Of course, our issue is whether the evidence against evolution will be taught along with that for evolution. Besides, the U.S. Constitution only states that “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof.” Our founding fathers, who acknowledged the Creator in many places, including the Declaration of Independence, did not want a national religion such as the Church of England. (The phrase “separation of church and state” is not in the Constitution. Nor is the word “separation” or the word “church.”)