Campaign speech includes empty platitude (9)
I believe the answer is:
operation
'campaign' is the definition.
(thesaurus)
'speech includes empty platitude' is the wordplay.
'speech' becomes 'oration' (oration is a kind of speech).
'includes' indicates putting letters inside.
'empty' says to hollow out the word (remove centre letters).
'platitude' with its middle taken out is 'pe'.
'oration' going around 'pe' is 'OPERATION'.
(Other definitions for operation that I've seen before include "Business" , "In hospital procedure" , "Action; process" , "running" , "management" .)