demagog vs politician

demagog and politician both are nouns.

Word	Noun	Adjective	Verb	Adverb
demagog	Yes	No	No	No
politician	Yes	No	No	No

As nouns, politician is a hypernym of demagog; that is, politician is a word with a broader meaning than demagog:

demagog: a political leader who seeks support by appealing to popular passions and prejudices
politician: a person active in party politics

Other hypernyms of demagog include pol, political leader, politico.

demagog (noun)	politician (noun)
a political leader who seeks support by appealing to popular passions and prejudices	a person active in party politics
	a leader engaged in civil administration
	a schemer who tries to gain advantage in an organization in sly or underhanded ways