Smear campaign and Whispering campaign

Whispering campaign and smear campaign are semantically related in attempt to defame another topic. In some cases you can use "Whispering campaign" instead a noun phrase "Smear campaign".

Whispering campaign noun - The organized dissemination of derogatory rumors designed to discredit a candidate.

Smear campaign and whispering campaign are semantically related in negative campaign topic. You can use "Smear campaign" instead a noun phrase "Whispering campaign".