A little power hurts Geronimo's people (7)
I believe the answer is:
apaches
'geronimo's people' is the definition.
(I've seen this in another clue)
'a little power hurts' is the wordplay.
'little' says to take the initial letters.
'hurts' becomes 'aches' ('ache' can be a synonym of 'hurt').
The initial letter of 'power' is 'p'.
'a'+'p'+'aches'='APACHES'
(Other definitions for apaches that I've seen before include "Native Americans" , "Indians" .)