Corrupt senator’s crime? (7)
I believe the answer is:
treason
'crime?' is the definition.
(treason is a kind of crime)
'corrupt senator's' is the wordplay.
'corrupt' indicates an anagram.
'senator' anagrammed gives 'TREASON'.
(Other definitions for treason that I've seen before include "Offence against state" , "One rats (anag)" , "Crime of disloyalty" , "Betrayal (of one's country)" , "Crime agains one's country" .)