Make a speech to only half the electorate (5)
I believe the answer is:
orate
'make a speech' is the definition.
(oratory is public speaking)
'only half the electorate' is the wordplay.
'only half' means to take half the letters.
'electorate' cut in half is 'ORATE'.
'to' acts as a link.
(Other definitions for orate that I've seen before include "Lecture" , "Speak pompously and at length" , "Declaim or rant" , "Make a formal speech" , "Speak in florid style" .)