Teddy Roosevelt successor (4)
I believe the answer is:
taft
'teddy roosevelt successor' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for taft that I've seen before include "US President before Wilson" , "US president, 1909-13" , "27th President of the United States" , "27th US president, William" , "former President" .)