Wise politician deals cunningly with matters in short space (5,9)
I believe the answer is:
elder statesman
'wise politician' is the definition.
'deals cunningly with matters in short space' is the wordplay.
'cunningly with' indicates an anagram.
'in' indicates putting letters inside.
'short space' becomes 'en' (typographical space as wide as an 'n').
'deals' with its letters mixed up with 'matters' gives 'lderstatesma'.
'lderstatesma' going within 'en' is 'ELDER STATESMAN'.
(Other definitions for elder statesman that I've seen before include "Wise old politician" , "member with gravitas" , "Experienced politician" , "veteran politician - with 17d" , "Perhaps Clinton" .)