One of the main arguments against ID is the accusation that it is an argument from ignorance or that is a science stopper. Personally, I think such claims are false and silly but people are entitled to believe in what they want. ID is falsifiable but not evolution.
For example, the flagellum is composed of numerous parts and they have to be assembled in the right order to work. What people like Behe and me included say that either all parts are assembled together at once or it could not have come by a step by step process because natural selection would not waste energy over something that is not providing benefit to the bacteria.
It seems obvious to me as a Biology undergrad how difficult it is for something as complex as this to be built in a step by step process yet many think there might be mechanisms that are still waiting to be discovered. For the sake of argument, lets say 50 years from now, we still don’t have a naturalistic explanation, would ID be considered as a valid explanation?