Trouble about Spain raised for a demarcated demographic? (3,5)
I believe the answer is:
age group
'a demarcated demographic?' is the definition.
(a demographic group)
'trouble about spain raised' is the wordplay.
'trouble' becomes 'aggro' (short for aggression).
'about' indicates putting letters inside.
'spain' becomes 'e' (abbreviation for Espana).
'raised' becomes 'up' (similar in meaning).
'aggro' enclosing 'e' is 'agegro'.
'agegro'+'up'='AGE-GROUP'
'for' acts as a link.
(Other definitions for age group that I've seen before include "contemporaries?" , "Old folk maybe" , "teenagers?" , "People of the same generation" , "Cohort" .)