Announced race led surprisingly by Democrat (8)
I believe the answer is:
declared
'announced' is the definition.
(similar in meaning)
'race led surprisingly by democrat' is the wordplay.
'surprisingly' is an anagram indicator (a surprising ordering of the letters).
'by' is a charade indicator (letters next to each other).
'democrat' becomes 'd'.
'race'+'led'='raceled'
'raceled' with letters rearranged gives 'declare'.
'declare'+'d'='DECLARED'
(Other definitions for declared that I've seen before include "Closed an innings" , "Announced formally" , "Spoke or said dramatically" , "Announced, proclaimed" , "Avowed openly" .)