Armor, I don't think a separate definition for 'red fascists' is even needed. The Soviet Union fulfills the basic definition just fine. It's the Nazi ideology that stands as the odd one out for being particular evil and racist, too. Going after the Jews is even meaner than just your average scapegoat-able group, because the Jews - as reflected in their Nobel price count - tend to contribute much above average to society.

That the Soviet Union routinely referred to the Nazis as 'fascists' clouds our preception of the Soviet system as fascist in itself. But that ourstanding exhibit in Moscow comparing Hitler and Stalin, just on their own words and deeds, demonstrated the similarity beyond doubt.

One basic principle that stands between democracy and fascist systems is the respect for private property. Fascism employs a corporate state of sorts, where the leadership can ursurp on the resources to feed their regime. Nazis did that particular by confiscating from the (frequently rich) Jews to fund their crimes and wars. Socialists probably won't like what I'm saying here, but a free market economy is the best antidote against totalitarian systems.

Today we have increasing problems with mob rule, like the very violent demonstrations for a 'Youth House' here in Denmark. I think one of the more important lessons from history is to not give in to intimidation. Unfortunately that seems to be a lesson lost on socialist politicians...

Did Robert O. Paxton also gave a historical definition for "red fascists" ?
I like the phrase "red fascists".

But mainly by those with keen historical awareness, I guess. I'll play around with it anyway, based on Wikipedia and my own ponderings.

Wikipedia has an article here, which refers to definitions by Robert O. Paxton:

Fascism may be defined as a form of political behavior marked by obsessive preoccupation with community decline, humiliation, or victim-hood and by compensatory cults of unity, energy, and purity, in which a mass-based party of committed nationalist militants, working in uneasy but effective collaboration with traditional elites, abandons democratic liberties and pursues with redemptive violence and without ethical or legal restraints goals of internal cleansing and external expansion."[11]

Paxton further defines fascism's essence as:

...a sense of overwhelming crisis beyond reach of traditional solutions; 2. belief one’s group is the victim, justifying any action without legal or moral limits; 3. need for authority by a natural leader above the law, relying on the superiority of his instincts; 4. right of the chosen people to dominate others without legal or moral restraint; 5. fear of foreign `contamination."[12]

Interestingly, some of these sentiments seem to apply to Islamic fundamentalists also.

Note: no racism or anti-semitism included here. That was specific to a somewhat related ideology north of the Alps.

Some elements I'd expect to see from fascists is the use of scapegoating, including the famous 'Big Lie' strategy, emotionalism trumphing the rule of law, mock trials, intimidation, vilification and eventual purging of dissidents, and a strong leader exploiting mob or military rule as an instrument to gag the opposition. Stalin would fit right in, right?

Understanding fascism is a requirement for standing up against it. Otherwise, it just becomes a pointless slur.