Ok so apparently my description of Social Marxism and the distinction between Marxism and Social Marxism was unclear. Allow me to expand on that concept.
Social Marxism is to Marxism as Social Darwinism is to Darwinian evolution; that is to say, it is a misappropriation of the labels and structures of Marxism to encompass a domain to which they do not apply. By Social Darwinism, I mean the concept that the working class are poor because they are inherently inferior and less fit to compete in the realm of politics and finances, and that giving them financial or social aid will only serve to encourage them to breed more like them. Where Darwinian evolution explains the appearance of species by means of survival of the fittest, Social Darwinism explains the appearance of class by means of procreation of the weak-minded and strong-minded, intelligent and stupid.
Social Marxism is not concerned primarily with the redistribution of wealth. That is a secondary concern to the distribution of social power; they believe that by more evenly distributing power, the wealth will redistribute itself. Social power is a somewhat nebulous concept; it's difficult to get an exact definition from the people who are framing the concept themselves. Social Marxists generally believe in a hierarchy of oppression based on their intersecting identities. If I was asked by someone who believed in the concept to produce a formulation of power in their worldview, I think I would describe it thusly:
Power is not directly connected to wealth. Wealth is a a function of power; that is to say, those with power will find it easier to achieve wealth. Power is directly connected to whiteness and masculinity. People who are white or can pass as white and who are male or can pass as male have inherent privileges within society, owing to nothing more than their perceived whiteness, sexuality, and gender identity. As a result of this, women, people of color and people of minority sexual orientations find it more difficult to succeed socially and financially, because they hold less power. To redistribute power, white men must be denied positions of power, such as jobs in media, jobs in government, jobs in management roles, and jobs in the police force and judicial system (where they can literally police black bodies). Because society is ruled by a cis white hetero capitalist patriarchy, and the white man is unwilling to give his power away, we must take it from them by force. This use is justified by the oppression [I don't know how to define this in their worldview] we are suffering as a direct result of their power.
That's why when Social Marxists march, they leave graffiti such as "Liberals get the bullet too". Although liberals may align with many of the concepts of Marxism as originally spelled out and consistently vote in favor of what would traditionally be seen as "socialist" options, such as a more even distribution of wealth, more socialization of public services such as the health service or increased public transportation, etc., they are not Social Marxists. Liberals believe that power is a function of wealth; Social Marxists believe that wealth is a function of power. Liberals believe that offering people freedom of choice and freedom from laws interfering with their ability to choose where they can go and what they can do will result in them making choices that will earn them wealth and by extension, power. Social Marxists believe that while white men have power, no other group can ever have wealth or true choice. Liberals believe that by reducing the cost (generally by socializing the production) of services geared towards social well-being, power will be evenly distributed from the "haves" to the "have nots", allowing the "have nots" the social mobility to either enter the ranks of the "haves" or at least be treated as equals by the "haves." Social Marxists believe that by redistributing power, the "have nots" will become the "haves", and in a few decades or centuries, when the balance of power has been in their hands for some time, they can reconsider the position of the white man in society.
The goals of Social Marxism do not reflect the opinions and beliefs of liberals. Social Marxism, instead of attempting to equalize the distribution of wealth via socializing the means of production, intends to equalize the distribution of power via the means of destroying "cis white hetero capitalist patriarchy", or some variation of that group.
Social Marxism is inherently a radical ideology that will only lead to radicalization and by extension, violence. They have no path to compromise in their ideology. They have no path to shared power. A black president, a female prime minister, women in the legislature, an equal representation of men and women in cabinets, none of these are, in their minds, truly representative of shared power. A white man can be, at best, an ally. He can never be an equal. He can never be a "true feminist", his life can never hold value unless he were to give it up for the cause of ending white power, he can never be anything more than a trained dog.
That's why the immediate demand is violence and the only tactic on offer is violence and intimidation. Intimidation doesn't just refer to physical intimidation, although it often involves that; it also refers to things like online bullying and harassment; calling one's employer to complain about their views; having people step down from their positions of power by means of protests and media witch hunts; denying white men or people they believe to be white men entry to their spaces (whether digital or physical) on the grounds that they create an unsafe environment; accusations of racism, misogyny, homophobia, transphobia, or some combination of these labels; calls for boycotts and no-platforming; and a variety of other tactics we have seen used in recent months.
Hopefully this sufficiently clarified what I mean by Social Marxism and who and what and I intend to use the term to refer to. As for the origins of the term, I think I heard someone else use it but I'm in the somewhat psychotic part of my depressive episode, and sometimes when I get like this I attribute my ideas and thoughts to other people, so I may have accidentally coined it. When I get like this it's often like being an oracle from the past--I hear thoughts in my head as if in another person's voice, but it's not an auditory hallucination, I'm aware that I'm thinking about the thing being said instead of simply hearing it said--and while the symptoms aren't as bad right now because of my medications, I'm still in a bit of a haze and feel more divorced from my brain and thoughts than usual.