Unhappy Democrat was the first charged (7)
I believe the answer is:
saddled
'charged' is the definition.
('saddle' can be a synonym of 'charge')
'unhappy democrat was the first' is the wordplay.
'unhappy' becomes 'sad' (similar in meaning).
'democrat' becomes 'd'.
'was the first' becomes 'led' (I've seen this in other clues).
'sad'+'d'+'led'='SADDLED'
(Other definitions for saddled that I've seen before include "Burdened with" , "stuck" , "Like a racehorse" , "Ready to ride" , "Horse might be" .)