Comic figure, a big hit entertaining the disheartened Republican (7)
I believe the answer is:
asterix
'comic figure' is the definition.
(comic book character)
'a big hit entertaining the disheartened republican' is the wordplay.
'big hit' becomes 'six' (cricket).
'entertaining' indicates putting letters inside (inviting in, as for dinner).
'disheartened' says to hollow out the word (remove centre letters) (the middle or heart is removed).
'republican' becomes 'R' (political abbreviation).
'the' with its middle removed is 'te'.
'te'+'r'='ter'
'six' going around 'ter' is 'sterix'.
'a'+'sterix'='ASTERIX'
(Other definitions for asterix that I've seen before include "Cartoon book Gaul" , "A Gaul, fought Romans (Goscinny)" , "French cartoon character" , "Gallic hero" .)