Assumes America excited about king getting success at last (6)
I believe the answer is:
usurps
'assumes' is the definition.
('usurp' can be a synonym of 'assume')
'america excited about king getting success at last' is the wordplay.
I cannot quite see how this works, but
'america' could be 'us' (United States) and 'us' is located in the answer.
'king' could be 'r' (abbreviation of Latin rex) and 'r' is found in the answer.
'excited' could be 'up' and 'up' is found in the remaining letters.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for usurps that I've seen before include "Takes a position of power illegally" , "Seizes and takes control without authority" , "Seize and hold by force" , "Encroaches upon" , "Takes position wrongfully or by force" .)