The fact that the Nazi's, despite their evil, gave birth to a very common weapon on Internet debates: Godwin's Law.Mere association with them also made card-carrying Fascism unacceptable among NATO countries.
They're nearly all depicted as straight white men of upper-to-middle class upbringing who view the UN, environmentalists, women and pretty much whoever has differing opinions to them as a threat.
Note that these words do not mean the same thing outside the United States.
Pol Pot was responsible for the deaths of at least 1.5 million Cambodian citizens, largely in the Cambodian Genocide of 1975-9 which reduced the population of the country by a fifth in an attempt to totally extirpate all non-Communist influences.
The few "Communist" governments which survived the collapse of the Soviet Union now largely exist in name only.
This too easily leads to making the other guy out to be a Straw Character.