Poisoning the well can be a special case of argumentum ad hominem, and the term was first used in this sense by John Henry Newman in his work Apologia Pro Vita Sua (1864).
[1] Poisoning the well can take the form of an (explicit or implied) argument, and is considered by some philosophers an informal fallacy.
In this pattern, an unfavorable attribute is ascribed to any future opponents, in an attempt to discourage debate.
Any person who steps forward to dispute the claim will then risk applying the tag to themselves in the process.
A poisoned-well "argument" can also be in this form:[3] Example: Boss, you heard my side of the story, and why I think Bill should be fired and not me.