EXPELLED does a good job of raising the issue it wishes to present in an entertaining and documented fashion. Many will mistake the issue as ID versus Darwinism. That is only the presenting occasion. The issue is Academic Freedom.
For those who think this is in any way distorted, they need only go to the Fall 1983 (Vol 8 no. 1) issue of the magazine Skeptical Inquirer. That issue reported on Iowa State University Professor John W. Patterson's contention that "every professor should reserve the right to fail any student in his class. no matter what the grade record indicates" and the institution should retract "grades and possibly even degrees" based on "gross misunderstanding". This latter phrase related to belief in creationism or failure to fully endorse the Professor's understanding of biological evolution.
The question was not agreement or disagreement with the Professor's convictions on creation, evolution, or Darwin, but whether students and/or Professors who did not agree had the right to offer/take/or pass courses in a public university.