The big problem IDers face is that there is no evidence at all to support their assertion that ID is a science.
So when someone challenges them, they can only try to distract you by switching the argument.
For example, the judge in the Dover Area School trial ruled that ID is not a science. Instead of arguing whether or not it is a science, Creationist retort is "How can a judge determine what is science or not?"
Two answers: Firstly a judge, judges. He looks at the evidence and makes a judgement. Just like Solomon, who didn't need to be an expert in genetics, he just needed to be able to get the evidence to decide. So when Judge Paul John Jones (a conservative Christian appointed by George Bush, by the way) decided that ID was not a science, he did so because science is clearly defined (the systematic study of the structure and behavior of the physical and natural world) and that definition excludes supernatural explanations. And further, there are good reasons for excluding supernatural explanations.
Secondly, Intelligent Design is a subterfuge, a deliberately deception to try to get Creationism into schools. That was clearly demonstrated by evidence produced during the trial, that over the past 25 years, the single textbook that the Creationists were pushing (Of Pandas and People) had been successively edited to change 'Creator' to 'Scientific Creator' to 'Intelligent Designer'. (And because they'd simply done a crude cut-and-paste job for some of the terms, the forensic evidence was hilariously evident.)
So instead of producing evidence to support the assertion that ID is science, Creationists will either attack Evolution ("Oh it hasn't proved this or that") or attack the person criticizing their position ("How are you qualified to judge what's scientific?")