Questions factions grabbing American power (8)
I believe the answer is:
suspects
'questions' is the definition.
(suspecting is a kind of questioning)
'factions grabbing american power' is the wordplay.
'factions' becomes 'sects' ('sect' can be a synonym of 'faction').
'grabbing' indicates putting letters inside.
'american' becomes 'us'.
'power' becomes 'p'.
'us'+'p'='usp'
'sects' enclosing 'usp' is 'SUSPECTS'.
(Other definitions for suspects that I've seen before include "Imagines to be true" , "Is inclined to believe" , "Fears" , "Believes to be guilty but without proof" , "Considers or believes likely" .)