A fabulous figure - a centrist politician and a graduate … (3,4)
I believe the answer is:
Here is my best explanation:
'a fabulous figure' is the definition.
(from the folktale 'Ali Baba and the Forty Thieves')
'a centrist politician and a graduate' is the wordplay.
'centrist politician' becomes 'lib' (abbreviation for liberal).
'and' means one lot of letters go next to another.
'graduate' becomes 'ba'.
(Other definitions for ali baba that I've seen before include "Arabian Nights hero who opposed forty thieves", "Pantomime character who took on 40 thieves", "Poor woodcutter and cave opener", "Arabian Nights hero who discovered 'Open sesame'", "pantomime hero", "Hero from Arabian Nights who said ''open sesame''", "One with forty theives", "He got involved with forty thieves", "associate of thieves" and "Fictional Arab with 40 thieves".)