Go over suggestion to involve Republican (4)
I believe the answer is:
trip
'go over' is the definition.
The answer and definition can be both acts as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'suggestion to involve republican' is the wordplay.
'suggestion' becomes 'tip' (tip is a kind of suggestion).
'to involve' means one lot of letters goes inside another (inserted letters get involved).
'republican' becomes 'r' (abbreviation).
'tip' going around 'r' is 'TRIP'.
Can you help me to learn more?
(Other definitions for trip that I've seen before include "Hallucinatory experience" , "(Cause to) fall" , "Ride" , "Journey, excursion" , "Catch one's foot" .)