Where one is struggling to become president (10)
I believe the answer is:
eisenhower
'president' is the definition.
(I've seen this before)
'where one is struggling' is the wordplay.
'struggling' indicates anagramming the letters.
'where'+'one'+'is'='whereoneis'
'whereoneis' anagrammed gives 'EISENHOWER'.
'to become' acts as a link.
(Other definitions for eisenhower that I've seen before include "General, President, 'Ike'" , "US president and general" , "1950s president" , "US president nineteen fifty three to nineteen sixty one" , "American general" .)