Dodgy religious group grabbing American power (7)
I believe the answer is:
suspect
'dodgy' is the definition.
(I've seen this before)
'religious group grabbing american power' is the wordplay.
'religious group' becomes 'sect' (I've seen this before).
'grabbing' is an insertion indicator.
'american' becomes 'us'.
'power' becomes 'p'.
'us'+'p'='usp'
'sect' placed around 'usp' is 'SUSPECT'.
(Other definitions for suspect that I've seen before include "Consider or believe likely" , "Have reason to believe" , "Possibly dangerous or false" , "Funny" , "One believed to have committed a crime" .)