ID is a peripheral, tentative, general approach to science. Science can, has, and does operate very well under the assumption that an intelligent designer is behind those things science investigates. There is no need to introduce it as a special topic or even give it a chapter in science books, although this should certainly not be prohibted by law. All the hubbub we are witnessing is over a tentative, yet reasonable, proposal regarding the bigger picture we all enjoy as observers.
When? What subject does that? Quantum Mechanics? Particle Physics? Volcanology? Meteorology?