Republican first lady to rip into minister (8)
I believe the answer is:
reverend
'minister' is the definition.
(I've seen this before)
'republican first lady to rip' is the wordplay.
'republican' becomes 'R' (abbreviation in US politics).
'first lady' becomes 'eve' (first woman in the Bible).
'to rip' becomes 'rend' (synonyms).
'r'+'eve'+'rend'='REVEREND'
'into' is the link.
(Other definitions for reverend that I've seen before include "Title of respect for a clergyman" , "Title of respect for a member of the clergy" , "like Father Brown" , "Clergyman's title" , "Title for clergyman or convent Mother" .)