Conservative nonsense leaving Democrat angry (5)
I believe the answer is:
cross
'angry' is the definition.
(cross can mean annoyed or angry)
'conservative nonsense leaving democrat' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'nonsense' becomes 'dross' (dross can mean nonsense or rubbish).
'leaving' suggests deleting specific letters.
'democrat' becomes 'd'.
'dross' with 'd' taken away is 'ross'.
'c'+'ross'='CROSS'
(Other definitions for cross that I've seen before include "something to bear" , "See 2" , "anger?" , "Sign - out of temper" , "Mad" .)