Utter slogan of a leftist? (8)
I believe the answer is:
outright
'utter slogan of a leftist?' is the definition.
'outright' can be an answer for 'utter' (I've seen this before). I am unsure of the 'slogan of a leftist?' bit.
'utter slogan of' is the wordplay.
I cannot really understand how this works, but
'utter' could be 'right' (both can mean complete or total) and 'right' is found within the answer.
'of' could be 'o' and 'o' is present in the answer.
The remaining letters 'ut' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for outright that I've seen before include "Immediately; openly" , "Completely - undisputed" , "Totally" , "Without reservation or exception" , "Completely - immediately" .)