Thus, in its relation to Christianity, intelligent design should be viewed as a ground-clearing operation that gets rid of the intellectual rubbish t… - William A. Dembski

Even many Christians who have been raised and indoctrinated in a secular mindset … will say, 'Look, we're just going to have to accept the science of the day and try to make our peace with it theologically.' … And there is no peace theologically … ultimately with this view [Darwinian evolution]. But they accept it. And so, this idea of intelligent design becomes very threatening.

Intelligent design is eminently falsifiable. Specified complexity in general and irreducible complexity in biology are within the theory of intelligent design the key markers of intelligent agency. If it could be shown that biological systems like the bacterial flagellum that are wonderfully complex, elegant, and integrated could have been formed by a gradual Darwinian process (which by definition is non-telic), then intelligent design would be falsified on the general grounds that one doesn't invoke intelligent causes when purely natural causes will do. In that case Occam's razor finishes off intelligent design quite nicely.

Design theorists are no friends of theistic evolution.