Can someone explain to me how the US government has the power to determine what is and what isnt science? The judge didnt even give an argument for why you cant consider ID in biology science even though the theory works in several other fields.

Not a single scientific or philosophical issue was addressed in this mock trial, by all science definitions, ID really is science. The only way to make a move against this position is to posit that all there is is material, which is is easily debunked by metaphysical, and scientific arguments.