campaigning vs stumping

campaigning and stumping both are nouns.

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

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

campaigning: the campaign of a candidate to be elected
stumping: campaigning for something by making political speeches (stump speeches)

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

campaigning (noun)	stumping (noun)
the campaign of a candidate to be elected	campaigning for something by making political speeches (stump speeches)