diehard

About 0.16 uses per million words.

Meaning

1. adjective Unreasonably or stubbornly resisting change.
2. adjective Fanatically opposing progress or reform.
3. adjective Complete; having no opposite opinion of anything in a particular topic of one's values; thorough of in one's beliefs.

   For a Roman Catholic teacher, he sure is a diehard fundamentalist.

4. adjective Strongly or fanatically determined or devoted.
5. noun A person with such an attitude.

Similar words

traditionalist stubborn obstinate stubbornness persistent intransigence recalcitrant intransigent tenacious persistence

Often followed by

fans supporters conservatives opponents conservative fan and anti opposition