A politician’s electronic device (3)
I believe the answer is:
amp
'electronic device' is the definition.
(amplifier)
'a politician's' is the wordplay.
'politician' becomes 'MP' (Member of Parliament).
'a'+'mp'='AMP'
(Other definitions for amp that I've seen before include "Device making sound louder" , "Sound booster" , "In short, unit for measuring electric current" , "Map of electric current" , "Map of electrical unit" .)