Back socialist after U-turn, right-wing politician being offensive (10)
I believe the answer is:
derogatory
'offensive' is the definition.
(I've seen this before)
'back socialist after u-turn right-wing politician' is the wordplay.
'back' becomes 'ago' ('years back' means 'years ago').
'socialist' becomes 'red' (socialism is often associated with the colour red).
'after u-turn' says the letters should be written in reverse.
'right-wing politician' becomes 'tory' (term for a Conservative Party politician. I am not sure about the 'right-wing' bit.).
'ago'+'red'='agored'
'agored' in reverse letter order is 'deroga'.
'deroga'+'tory'='DEROGATORY'
'being' acts as a link.
Can you help me to learn more?
(Other definitions for derogatory that I've seen before include "Insulting" , "deliberately offensive" , "Showing a disrespectful attitude" , "Disparaging" .)