Pitiful tale of son of a bitch and Southern politician (3,5)
I believe the answer is:
sob story
'pitiful tale' is the definition.
(I've seen this before)
'son of a bitch and southern politician' is the wordplay.
'son of a bitch' becomes 'SOB' (synonyms).
'and' says to put letters next to each other.
'southern' becomes 's' (abbreviation).
'politician' becomes 'tory' (term for a Conservative Party politician).
'sob'+'s'+'tory'='SOB-STORY'
'of' acts as a link.
(Other definitions for sob story that I've seen before include "appeal to emotions" , "Affecting tale (colloq.)" , "Tear-jerking account" , "Pathetic tale" , "Tale intended to arouse pity" .)