Props up Marx reportedly propping up leaders of Soviet Union (8)
I believe the answer is:
sustains
'props up marx' is the definition.
I can't tell whether this definition defines the answer.
'reportedly propping up leaders of soviet union' is the wordplay.
'reportedly' becomes 'stains' (I can't justify this - if you can you should believe this answer much more).
'propping up' is a charade indicator (letters next to each other).
'leaders of' says to take the initial letters.
The initial letters of 'soviet union' is 'su'.
'stains' after 'su' is 'SUSTAINS'.
Can you help me to learn more?
(Other definitions for sustains that I've seen before include "Bears" , "Supports, keeps alive" , "keeps going" , "Provides with nourishment" , "Supports physically or mentally" .)