Brown coats unusual for top Democrat (6)
I believe the answer is:
truman
'top democrat' is the definition.
(former US president Harry Truman)
'brown coats unusual' is the wordplay.
'brown' becomes 'tan' (tan is a kind of brown).
'coats' means one lot of letters goes inside another.
'unusual' becomes 'rum' (I've seen this before).
'tan' placed around 'rum' is 'TRUMAN'.
'for' is the link.
(Other definitions for truman that I've seen before include "- - Capote (lit.)" , "Harry S ..., former president of USA" , "33rd president of the United States, d. 1972" , "Harry S ... former US president" , "Harry S ...... was USA president 1945-53" .)