Crime against the state involving a crooked senator (7)
I believe the answer is:
treason
'crime against the state' is the definition.
(I've seen this before)
'a crooked senator' is the wordplay.
'a crooked' is an anagram indicator (a crooked or disrupted version of the letters).
'senator' with letters rearranged gives 'TREASON'.
'involving' is the link.
(Other definitions for treason that I've seen before include "Lese-majesty" , "subversion" , "Senator (anag)" , "Mutiny" , "Crime of disloyalty" .)