Advocates of Intelligent Design (ID) claim that ID makes real predictions. In particular, they predict that there will be gaps in the fossil record, and that the designer would create life by re-using existing organic technology (i.e., we will see common descent).
Now anyone who has even watched a documentary on evolutionary biology knows that a) the fossil record has gaps, and b) that there is common descent.
ID is a scam. They claim to predict what they already know to be the case.
But what does ID really predict?
Fossils are only preserved in very rare cases, like when an animal dies and is washed into a river bed and buried in fine silt. So gaps in the fossil record are what we should expect, no matter what the origin of life.
Common descent is the one thing specifically not predicted by ID. There's no reason why a designer should reuse DNA technology in every life form, and no reason why species should appear to have common ancestry. A designer could put rabbits in the Precambrian and robot mice in the Cretaceous. That's what ID predicts. Of course, nothing like this has ever been found, so ID doesn't claim this prediction.
By itself, ID makes no real predictions, because the designer could have done anything for any reason. Instead, generic ID merely predicts that we can't explain the origins of life. That's not a falsifiable theory, and it's definitely not science.
ID could render itself a science by making specific claims about the designer. What is she like? What tools did she use, and why did she use them? Where are those tools now? How did the limitations of the designer lead to the designs we see today? Needless to say, ID proponents, who are religiously motivated, won't go there.
ID experts claim to be the peers of scientists. But they're not. They are not fellow detectives trying to solve a mystery. They are defense attorneys for God, arguing that the detectives can't prove their case. The scientific jury isn't buying it, so they have to try their case in the court of public opinion.