favorite son vs nominee

favorite son and nominee both are nouns.

Word	Noun	Adjective	Verb	Adverb
favorite son	Yes	No	No	No
nominee	Yes	No	No	No

As nouns, nominee is a hypernym of favorite son; that is, nominee is a word with a broader meaning than favorite son:

favorite son: a United States politician favored mainly in his or her home state
nominee: a politician who is running for public office

Other hypernyms of favorite son include campaigner, candidate.

favorite son (noun)	nominee (noun)
a United States politician favored mainly in his or her home state	a politician who is running for public office