Backed minister to approve law, obtaining an easy victory (8)
I believe the answer is:
walkover
'an easy victory' is the definition.
(I've seen this before)
'backed minister to approve law' is the wordplay.
'backed' says the letters should be written backwards.
'minister' becomes 'rev' (short for reverend).
'to approve' becomes 'ok' ('ok' can be a synonym of 'approve').
'rev'+'ok'+'law'='revoklaw'
'revoklaw' in reverse letter order is 'WALKOVER'.
'obtaining' acts as a link.
(Other definitions for walkover that I've seen before include "easy win" , "Uncontested race" , "An easy victory - stroll across" , "Unopposed victory" , "Easy victory of ambulant sort?" .)