Small piece that’s extra about Southern Liberal (6)
I believe the answer is:
morsel
'small piece' is the definition.
(I've seen this before)
'extra about southern liberal' is the wordplay.
'extra' becomes 'more' (I've seen this before).
'about' indicates putting letters inside.
'southern' becomes 'S' (abbreviation).
'liberal' becomes 'l' (abbreviation).
'more' going around 's' is 'morse'.
'morse'+'l'='MORSEL'
'that's' is the link.
(Other definitions for morsel that I've seen before include "A shred as of bread" , "Just a fragment of food" , "A tiny bit" , "Tidbit" , "Scrap, fragment" .)