Emotional pang among left-wingers (6)
I believe the answer is:
twinge
'emotional pang' is the definition.
(I've seen this before)
'among left-wingers' is the wordplay.
'among' indicates the answer is hidden within the clue.
'TWINGE' can be found hidden inside 'left wingers'.
(Other definitions for twinge that I've seen before include "Sharp pang" , "Slight ache" , "A slight stab of pain" , "Spasm" , "Sudden localised pain" .)