Pressure from smear surrounding Republican (6)
I believe the answer is:
strain
This could be a double definition.
'pressure' is the first definition.
(thesaurus)
'smear surrounding republican' is the second definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'from' is the link.
Can you help me to learn more?
(Other definitions for strain that I've seen before include "Great effort - sieve" , "line of ancestry" , "Wrench; melody" , "Exert oneself to the utmost" , "Tension on trains" .)