I think your reference is only a survey of state laws. Additionally to those, federal law prohibits different kinds of discrimination as well. For example, Title IX [1] protects discrimination on sex in all states. Although political discrimination doesn't seem to fall under any federal law. An interesting discussion of religious versus political discrimination is here: http://lists.ucla.edu/pipermail/religionlaw/1998-August/0129...

1. http://en.wikipedia.org/wiki/Title_IX