State of heightened activity concerning campaign push (9)
I believe the answer is:
overdrive
'state of heightened activity' is the definition.
(as in going into overdrive)
'concerning campaign push' is the wordplay.
'concerning' becomes 'over' (both can mean relating to).
'campaign push' becomes 'drive' (drive can mean a campaign or initiative).
'over'+'drive'='OVERDRIVE'
(Other definitions for overdrive that I've seen before include "gear for cruising" , "Engine mechanism" , "Extra-high gear" , "It gets you going fast" , "Gear above usual top gear" .)