Deadlock that is about politician and fool (7)
I believe the answer is:
impasse
'deadlock' is the definition.
(synonyms)
'that is about politician and fool' is the wordplay.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'about' is an insertion indicator.
'politician' becomes 'MP' (Member of Parliament).
'and' is a charade indicator (letters next to each other).
'fool' becomes 'ass' (both can mean a stupid person).
'mp'+'ass'='mpass'
'ie' placed around 'mpass' is 'IMPASSE'.
(Other definitions for impasse that I've seen before include "Deadlock or stand-off" , "Situation in which progress is impossible" , "There's no way past it" , "cul-de-sac" , "nothing can be done" .)