Tom cared about being a politician (8)
I believe the answer is:
democrat
'a politician' is the definition.
(Democrat is an example)
'tom cared about' is the wordplay.
'about' indicates anagramming the letters.
'tom'+'cared'='tomcared'
'tomcared' with letters rearranged gives 'DEMOCRAT'.
'being' acts as a link.
(Other definitions for democrat that I've seen before include "Republican's US rival" , "Believer in popular government" , "Advocate of government by elected representatives" , "Clinton or Obama supporter" , "One advocates government by the people's elected representatives" .)