Right-winger, originally Trotskyist, that Blair, perhaps, welcomes (11)
I believe the answer is:
thatcherite
'right-winger' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'originally trotskyist that blair perhaps welcomes' is the wordplay.
'originally' indicates taking the first letters.
'blair perhaps' becomes 'Cherie' (Cherie Blair, wife of Tony Blair).
'welcomes' is an insertion indicator.
The initial letter of 'trotskyist' is 't'.
'that'+'cherie'='thatcherie'
't' put within 'thatcherie' is 'THATCHERITE'.
Can you help me to learn more?
(Other definitions for thatcherite that I've seen before include "One supporting former PM's policies" , "Old Maggie fan" , "Type of Conservative" , "Conservative politician" , "old political supporter" .)