Frame piece of legislation introduced by socialist (6)
I believe the answer is:
redact
'frame' is the definition.
(synonyms)
'piece of legislation introduced by socialist' is the wordplay.
'piece of legislation' becomes 'act' (I've seen this in another clue).
'introduced by' is a charade indicator (letters next to each other).
'socialist' becomes 'red' (socialism is often associated with the colour red).
'act' put after 'red' is 'REDACT'.
(Other definitions for redact that I've seen before include "Edit for publication" , "put into literary form" , "Prepare for publication" , "Prepare to publish" , "Traced badly to edit" .)