Assuming power, Republican gets rich after term in office (12)
I believe the answer is:
presumptuous
'assuming power republican' is the definition.
'presumptuous' can be an answer for 'assuming' (presumptuous can mean making assumptions). I am unsure of the 'power republican' bit.
'rich after term in office' is the wordplay.
'rich' becomes 'sumptuous' (similar in meaning).
'after' is a charade indicator (letters next to each other).
'term in office' becomes 'pre' (I can't explain this - if you can you should believe this answer much more).
'sumptuous' put after 'pre' is 'PRESUMPTUOUS'.
'gets' acts as a link.
Can you help me to learn more?
(Other definitions for presumptuous that I've seen before include "Bold - forward" , "Assuming too much" , "Impertinently bold" , "Impertinent" .)