Revolutionary base — that one’s smoking? (7)
I believe the answer is:
cheroot
'that one's smoking?' is the definition.
(type of cigar)
'revolutionary base' is the wordplay.
'revolutionary' becomes 'che' (Che Guevara the Marxist revolutionary).
'base' becomes 'root' (synonyms).
'che'+'root'='CHEROOT'
(Other definitions for cheroot that I've seen before include "Small cigar" , "Cigar with open ends - hot core (anag)" , "Cigar cut at both ends" , "Havana?" , "Type of cigar" .)