Intelligent design has explanatory power, especially given Dembski's
"explanatory filter." It accounts for a wide range of biological facts.
This makes it scientific.
Merely accounting for facts does not make a theory scientific. Saying
"it's magic" can account for any fact anywhere but is as far from
science as you can get. A theory has explanatory power if facts can be
deduced from it. No facts have ever been deduced from ID theory. The
theory is equivalent to saying, "it's magic."
Dembski's explanatory filter requires the
examination of an
infinite number of other hypotheses -- even unknown ones -- to accept
the design hypothesis. Thus it is impossible to apply. Intelligent
design remains untestable and impossible to use in practice.
Dembski himself has never rigorously applied his filter (Elsberry 2002).
"Intelligent" and "design" remain effectively undefined. A theory
cannot have explanatory power if it is uncertain what the theory says
in the first place.