political dissident vs objector

political dissident and objector both are nouns.

Word	Noun	Adjective	Verb	Adverb
political dissident	Yes	No	No	No
objector	Yes	No	No	No

As nouns, objector is a hypernym of political dissident; that is, objector is a word with a broader meaning than political dissident:

Other hypernyms of political dissident include contestant, dissenter, dissident, protester.

political dissident (noun)	objector (noun)
a dissenter from political orthodoxy	a person who dissents from some established policy