Generally a matter of choice (8)
I believe the answer is:
election
'choice' is the definition.
(I know that election is a type of choice)
'generally a matter' is the wordplay.
I cannot quite see how this works, but
'matter' could be 'ion' (ion is a kind of matter) and 'ion' is found within the answer.
The remaining letters 'elect' 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).
'of' acts as a link.
Can you help me to learn more?
(Other definitions for election that I've seen before include "Polling process" , "Time for political change" , "Selection by ballot" , "Time to vote" , "Process of choosing a government" .)