Excellent scientists are lining up to play the admittedly entertaining game of seeing who can think up the cleverest way to explain what's wrong with "Intelligent Design" to other excellent scientists. This is not only pointless, but reinforces the companionably inane idea that scientists find "Intelligent Design" threatening, which of course they do not, since anybody actually teaching high-school biology will naturally dispose of non-scientific objections in the process of explaining the whole concept of science to begin with. Scientists object to "Intelligent Design" not because it is threatening, but because it is insulting.  

Here is an attempt, then, to explain both what's wrong with the idea, and why intelligent (as opposed to "Intelligent") people hate that there even needs to be a discussion over it.  

1. Reading a statement about "Intelligent Design" at the beginning of a high-school biology class is like reading a statement about Scientology at the beginning of a Catholic mass.  

2. The government requiring high-school biology teachers to read a statement about "Intelligent Design" at the beginning of their classes is like the government requiring Catholic priests to read a statement about Scientology at the beginning of their masses.  

3. More precisely, because high-school biology is hard enough to teach to begin with, the government requiring high-school biology teachers to read a statement about "Intelligent Design" at the beginning of their classes is like the government requiring Catholic priests to read a statement about Scientology, in English, at the beginning of a Latin mass.  

If you can find an actual person who thinks "Intelligent Design" belongs in schools, try that on them, and let me know if it helps.