They absolutely DO NOT want to allow ANYTHING other than evolution to be taught in schools.
No, they just want to limit science classes to actual science. They're funny that way.
One of the primary theorems is that living things started out as mere self replicating amino acids and through an extremely long process of total random accidents that cannot be explained, became single celled organisms, then multi-celled organism, then eventually human beings.
Also, we are supposed to believe that evolution went from self replicating amino acids to trillions and trillions of extremely specialized cells working together in the mere blink of 4.5 billion years. How many changes must one undertake to complete the transformation from amoeba-like blob to human being? A million? Probably more like a billion or even much more.
So, which is it? Did it happen slowly and gradually or suddenly in bursts as must happen?
No matter what you say, evolution is a belief system whose theories CANNOT be tested.