Cross in favour of Democrat (4)
I believe the answer is:
ford
'cross' is the definition.
(fording is a kind of crossing)
'in favour of democrat' is the wordplay.
'in favour of' becomes 'for' (I've seen this before**).
'democrat' becomes 'd'.
'for'+'d'='FORD'
(Other definitions for ford that I've seen before include "way for pedestrians" , "River or stream crossing" , "Shallow area in a stream where it can be crossed" , "Harrison - - (film actor)" , "US President - river crossing" .)