Tendency Democrat is showing in part of speech (14)
I believe the answer is:
predisposition
'tendency' is the definition.
(I've seen this before)
'democrat is showing in part of speech' is the wordplay.
'democrat' becomes 'd'.
'showing in' indicates putting letters inside.
'part of speech' becomes 'preposition' (I've seen this before).
'd'+'is'='dis'
'dis' put within 'preposition' is 'PREDISPOSITION'.
(Other definitions for predisposition that I've seen before include "Inclination (to behave in certain ways)" , "Prior inclination (towards something)" , "Bent" , "Existing inclination (to react in a certain way)" , "A tendency (to do something)" .)