Republican bound by idiotic plan (5)
I believe the answer is:
draft
'plan' is the definition.
(drafting is a kind of planning)
'republican bound by idiotic' is the wordplay.
'republican' becomes 'R' (abbreviation in US politics).
'bound by' is an insertion indicator (inserted letters are held or bound).
'idiotic' becomes 'daft' (I've seen this before).
'r' put inside 'daft' is 'DRAFT'.
(Other definitions for draft that I've seen before include "Rough drawing" , "sketch, perhaps" , "Written plan" , "form of conscription" , "book's outline" .)