Full Idea
The originator of 'intelligent design' (the biochemist Michael Behe) takes every phenomenon whose evolutionary history has not yet been figured out, and chalks it up to design by default.
Gist of Idea
Intelligent Design says that every unexplained phenomenon must be design, by default
Source
Steven Pinker (The Blank Slate [2002], Ch.7)
Book Reference
Pinker,Steven: 'The Blank Slate' [Penguin 2003], p.130
A Reaction
This seems to summarise the strategy very nicely. The theory essentially exploits the 'wow!' factor. The bigger the wow! the more likely it is that it was created by God. But research has been eroding our wows steadily for four hundred years.