Actually I don't think this is the case. We don't want ID taught in the classroom because it is not science, it can not be. As far as I can imagine, God is not testable by science, so no hypothesis will ever be added to science which supports God's existence. Thus science will not lead us to support the existence of God, even if He does exist.
This is why the ID-proponent spends so much time poking at those areas where weakness is seen in evolution. If a scientific hypothesis can not be submitted supporting his belief, then the next best thing is to attack that which threatens the belief. Ironically these attacks only strengthen evolution as answers are sought out to explain those weaknesses.
(Disclaimer: I do believe in God and that He is our creator. I leave a place for evolution, but am not overly concerned by it.)
God may be subtle, but he isn't plain mean. -- Albert Einstein