[lonestar67]

Thus far, however, all ID movements are decidedly Christian in origin . ..

This is not true and this is very much part of the problem. Once Christian supporters of an idea are found, that becomes the legal basis of exclusion. Science is regularly intermingled with non-scientific nonsense including religious views and they are not attacked by science purists-- at least not in the highly dramatic way that creationist and ID proponents.

At my own state university, courses promoting the integration of Buddhism and biology are applauded and encouraged without separation accusations.

[Dimensio]

Once Christian supporters of an idea are found, that becomes the legal basis of exclusion.

There are plenty of Christians who accept the theory of evolution and plenty of Christians who accept relativity theory and plenty of Christians who accept the Big Bang theory.

The difference is that the aforementioned theories are a direct result of observations in the universe while ID is a direct result of a subset of Christians looking for a scientific wrapper for their predetermined religious beliefs.