campaigning vs hustings

campaigning and hustings both are nouns.

Word	Noun	Adjective	Verb	Adverb
campaigning	Yes	No	No	No
hustings	Yes	No	No	No

As nouns, hustings is a hyponym of campaigning; that is, hustings is a word with a more specific, narrower meaning than campaigning:

campaigning: the campaign of a candidate to be elected
hustings: the activities involved in political campaigning (especially speech making)

Other hyponyms of campaigning include front-porch campaign, front-porch campaigning, whispering campaign, stumping.

campaigning (noun)	hustings (noun)
the campaign of a candidate to be elected	the activities involved in political campaigning (especially speech making)