On Mastodon, anyone on earth can attach slurs, hate speech, threats, or shock images to any post the campaign makes. The nature of federation and the design of mastodon is such that this cannot be prevented.
It may or may not be visible to the campaign. It may or may not be visible to any individual user. It may or may not be visible to the server moderators.
Mastodon is fundamentally unsuited to this scenario.