Ruth and I are upset about politician making a success (7)
I believe the answer is:
triumph
'a success' is the definition.
(I know that triumph is a type of success)
'ruth and i are upset about politician' is the wordplay.
'and' says to put letters next to each other.
'are upset' indicates anagramming the letters.
'about' indicates putting letters inside.
'politician' becomes 'MP' (Member of Parliament).
'ruth' put after 'i' is 'iruth'.
'iruth' with letters rearranged gives 'triuh'.
'triuh' placed around 'mp' is 'TRIUMPH'.
'making' acts as a link.
(Other definitions for triumph that I've seen before include "hit" , "motorbike" , "Prove superior" , "Outstanding victory" , "Crow" .)