As your GetReligionistas have stressed a gazillion times, that is why the term has its own cautious entry in the Associated PRess Stylebook:
“fundamentalist: The word gained usage in an early 20th century fundamentalist-modernist controversy within Protestantism. In recent years, however, fundamentalist has to a large extent taken on pejorative connotations except when applied to groups that stress strict, literal interpretations of Scripture and separation from other Christians.
“In general, do not use fundamentalist unless a group applies the word to itself.”
Alas, whenever this term is used by the media, you can be assured that it’ll have almost nothing in common with its original meaning.
Here’s how we got the term: In the early 1900s a conservative movement sprung up within Protestantism — including the mainstream Protestant churches — in reaction to liberal theology and the form of Biblical interpretation known as higher criticism. A series of articles was written and collected into a four-volume work called The Fundamentals which was intended to outline the key doctrines, the “fundamentals”, of the Christian faith. The movement eventually moved away from its intellectual roots, though, and by the end of World War II it had receded from the culture at large.
Nowadays, though, the term “fundamentalist” has become synonymous with just about any strict conservative stance in any religion or ideology. Once again, it pays to remember that the AP stylebook notes that it has “taken on a pejorative connotations” and advises avoiding it unless a group applies it to themselves.
Unfortunately, that suggestion is rarely followed and the label is applied in seemingly contradictory ways. Take, for example, the title of a report an ABC New’s Nightline: ‘Modern Polygamy: Arizona Mormon Fundamentalists Seek to Shed Stereotypes.’
The story contrasts a group of “1,500 fundamentalist Mormons” living in Centennial Park, Ariz. with another group of nearby polygamists, “the Fundamentalist Church of Jesus Christ of Latter-Day Saints followers, or FLDS, the group led by self-described prophet Warren Jeffs.” There’s no indication the Centennial Park polygamists call themselves fundamentalists so why use the term to compare them with a group that does?
The “stereotype” referred to in the title is that Mormon polygamy is repressive to women: