The most common and most likely answer to this crossword clue is the 8 letter word DIEHARDS
I've seen this crossword clue in Financial Times
D
I
E
H
A
R
D
S
More clues leading to the result DIEHARDS
- Detective Inspector Morse ultimately tough on southern reactionaries
- Pass on meeting solid Brexiteers; ultimately they won’t change their minds
- Ultra-conservatives dread his becoming revolutionary
- 6 Inwardly unfeeling, succumbs to those that won’t be moved
- Papers, in review: ‘Has red transformed ultra-conservatives?’
Buddy explains!
The straight part
We know that "they won’t change their minds" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case they won’t change their minds = diehards.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DIEHARDS mean?
DIEHARDS noun- A person with such an attitude.