Unequally carve up goose, madly merry tucking in (11)
I believe the answer is:
gerrymander
'unequally carve up' is the definition.
(gerrymandering is drawing electoral maps unfairly)
'goose madly merry tucking in' is the wordplay.
'goose' becomes 'gander' (gander is a kind of goose).
'madly' indicates an anagram.
'tucking in' is an insertion indicator.
'merry' with letters rearranged gives 'errym'.
'gander' placed around 'errym' is 'GERRYMANDER'.
(Other definitions for gerrymander that I've seen before include "Perform political chicanery with voting areas" , "Rig vote" , "Rearrange voting areas to benefit one party" , "Be politically dishonest" , "Redo edges of seats" .)