Ministers persist in a stupid way (7)
I believe the answer is:
priests
'ministers' is the definition.
(church ministers)
'persist in a stupid way' is the wordplay.
'in a stupid way' is an anagram indicator.
'persist' with letters rearranged gives 'PRIESTS'.
(Other definitions for priests that I've seen before include "Religious leaders" , "Spiritual leaders" , "Ordained ministers" , "Clerics" , "Church leaders" .)