Accuse one politician? Every one! (7)
I believe the answer is:
impeach
'accuse' is the definition.
('impeach' can be a synonym of 'accuse')
'one politician? every one' is the wordplay.
'one politician?' becomes 'imp' (I've seen this in other clues).
'every one' becomes 'each' (I've seen this before).
'imp'+'each'='IMPEACH'
(Other definitions for impeach that I've seen before include "Charge with a crime (against the state)" , "In America, charge with misconduct - say President" , "Accuse of serious crime against the state, say treason" , "Charge with treason, etc" , "Charge public official with misconduct - Clinton?" .)