sachem vs politician

sachem and politician both are nouns.

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

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

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

sachem (noun)	politician (noun)
a chief of a North American tribe or confederation (especially an Algonquian chief)	a person active in party politics
a political leader (especially of Tammany Hall)	a leader engaged in civil administration
	a schemer who tries to gain advantage in an organization in sly or underhanded ways