Relation huffs about possible Congressional result (9)
I believe the answer is:
stepchild
'relation' is the definition.
(stepchild is a kind of relation)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for stepchild that I've seen before include "Spouse's son or daughter from a previous marriage" , "Offspring of spouse" , "Somebody else's kid" , "Cinderella, perhaps" .)