Note rise of US writer they condemned as a mere beginner (8)
I believe the answer is:
neophyte
'a mere beginner' is the definition.
(a neophyte is a beginner or novice)
'note rise of us writer they condemned' is the wordplay.
'note' becomes 'n' (abbreviation).
'rise of' says the letters should be written in reverse.
'us writer' becomes 'poe' (Edgar Allan Poe).
'condemned' indicates anagramming the letters.
'poe' in reverse letter order is 'eop'.
'they' with letters rearranged gives 'hyte'.
'n'+'eop'+'hyte'='NEOPHYTE'
'as' acts as a link.
(Other definitions for neophyte that I've seen before include "newcomer on the scene" , "One's just taken orders" , "They open for a new convert" , "Newcomer, starter" , "Novice of religious order, or new convert" .)