Republican plugs a live diatribe deviating from the acceptable (8)
I believe the answer is:
aberrant
'deviating from the acceptable' is the definition.
'republican plugs a live diatribe' is the wordplay.
'republican' becomes 'r' (abbreviation).
'plugs' means one lot of letters goes inside another (plug can mean to fill a gap).
'live' becomes 'be' ('be' can be a synonym of 'live'**).
'diatribe' becomes 'rant' (I've seen this in other clues).
'a'+'be'+'rant'='aberant'
'r' put inside 'aberant' is 'ABERRANT'.
(Other definitions for aberrant that I've seen before include "Irregular" , "Deviating from what is accepted" , "Deviating from the norm, at barren state" , "rogue" , "Transgressing" .)