Plan to avoid Republican discussion (4)
I believe the answer is:
chat
'discussion' is the definition.
(chat can mean a conversation)
'plan to avoid republican' is the wordplay.
'plan' becomes 'chart' (chart can mean a plan or diagram).
'to avoid' is a deletion indicator.
'republican' becomes 'R' (abbreviation in US politics).
'chart' with 'r' taken out is 'CHAT'.
(Other definitions for chat that I've seen before include "Small songbird of the thrush family" , "Talk casually" , "Exchange text or voice messages through a computer" , "Chinwag" , "Rabbit" .)