A straw man is a fallacious propaganda method, in which someone sets up a false description of an opponent's view and arguments, and which are then easily dismissed.
Straw man arguments are commonly used by race denialists.
Another common example is the "conspiracy theory" label, which may involve falsely stating that an opponent is claiming a conspiracy theory or misrepresenting an opponent's conspiracy theory. See, for example, Wikipedia: "White genocide conspiracy theory" and Islamization and anti-Islamization: Eurabia.
Attacks on Holocaust revisionism frequently involve attacking straw men versions of what Holocaust revisionists argue, as discussed in several places in the article on Anti-Holocaust revisionism.