Republicans, left with the winning cards, will be successful (2,6)
I believe the answer is:
go places
'be successful' is the definition.
(I've seen this before)
'republicans left with the winning cards' is the wordplay.
'republicans' becomes 'gop' (the Grand Old Party, nickname for US Republicans).
'left' becomes 'l' (common abbreviation).
'with' is a charade indicator (letters next to each other).
'the winning cards' becomes 'aces' (I've seen this in another clue).
'gop'+'l'+'aces'='GO PLACES'
'will' acts as a link.
(Other definitions for go places that I've seen before include "Succeed" , "flourishing" , "Be successful; travel (colloq.)" .)