Fresh denial by Democrat about weed (9)
I believe the answer is:
dandelion
'weed' is the definition.
(plant classified as a weed)
'fresh denial by democrat about' is the wordplay.
'fresh' is an anagram indicator (a fresh re-ordering of the letters).
'by' means one lot of letters go next to another.
'democrat' becomes 'd'.
'about' becomes 'on' (as in a book 'on' a certain topic).
'denial' is an anagram of 'andeli'.
'andeli' put after 'd' is 'dandeli'.
'dandeli'+'on'='DANDELION'
(Other definitions for dandelion that I've seen before include "Wild flower with serrated leaves" , "salad plant" , "Wild plant with "clock"" , "Flower with a "clock"" , "One blooming" .)