Lose voter? Terrible for president (9)
I believe the answer is:
roosevelt
'president' is the definition.
(Theodore Roosevelt or Franklin Delano Roosevelt)
'lose voter? terrible' is the wordplay.
'terrible' is an anagram indicator.
'lose'+'voter'='losevoter'
'losevoter' anagrammed gives 'ROOSEVELT'.
'for' is the link.
(Other definitions for roosevelt that I've seen before include "Leading statesman in war" , "Surname of 26th and 32nd US presidents" , "See president" , "Name of two twentieth century US presidents" , "Long-term leader" .)