Running mate made Republican top candidates (5,4)
I believe the answer is:
dream team
'top candidates' is the definition.
'running mate made republican' is the wordplay.
'running' is an anagram indicator.
'republican' becomes 'r' (abbreviation).
'mate'+'made'+'r'='matemader'
'matemader' with letters rearranged gives 'DREAM TEAM'.
(Other definitions for dream team that I've seen before include "Group considered as perfect for a given task" , "Ideal combination" , "Perfect combination of people for a task" , "An ideal mix of people" .)