Corrupt banks earn from American state (9)
I believe the answer is:
nebraskan
'from american state' is the definition.
(from Nebraska)
'corrupt banks earn' is the wordplay.
'corrupt' indicates anagramming the letters.
'banks'+'earn'='banksearn'
'banksearn' is an anagram of 'NEBRASKAN'.
(Other definitions for nebraskan that I've seen before include "Statesman" , "One from Omaha" , "Lincoln resident?" , "inhabitant of Lincoln, possibly" .)