Radical liberals are the non-revolutionary left. They sometimes call themselves Greens, labor, socialist, communist, anarchist or some ideological subset of human identity; but they never advocate for social revolution. As a plus, many radical liberals advocate reforms of the system of wage labour which give some of the collective product of labour, including some labour time, back to the producers of the wealth of nations. Sometimes radical liberals even advocate for national liberation. Specifically though, radical liberals never advocate for a change in the mode of production and exchange.
Marx and Engels were social revolutionaries who advocated the abolition of the wage system, common ownership of the collective product of labour and production of wealth for use, with its distribution based on need e.g. communism. The defining characteristics of a social revolution are rooted in a change in the mode of production and exchange. Radical liberals content themselves with advocating reforms of the rule of Capital; but never the total obliteration of Capital as a social relation. They typically advocate a fair wage system with social justice and usually call it, 'being realistic'. With their political pragmatism in hand, they barrack for good rulers to replace evil rulers and, never for a free association of producers, democratically managing the whole the collective product of labour. The self-described anarchists and Communists amongst them sometimes advocate for an equality of wages, not the abolition of the wage system. Some radical liberals calling themselves libertarian socialists advocate for worker owned cooperatives to replace corporations with the aim of restoring fairness and social justice to the marketplace for commodities through genuine competition between enterprises of wage-slaves engaged in self-management, not an end to commodity production and sale and distribution of socially owned use-values on the basis of need.
Radical liberalism dominates political, social and cultural discourse on the left. With their identity politics in hand, they dream of ending racism, sexism, ageism, classism etc. while promoting environmentalism to achieve social justice under the rule of Capital. For radical liberals, changing the mode of production is an out dated way to approach social justice, one which smacks of bureaucratic State socialism.
Radical liberals may talk of revolution; but they haven't got a clue about what a social revolution from class dominated to classless society would entail in terms of sublating the capitalist mode of production, although many of the more reactionary amongst them advocate a return to pre-capitalist modes of production. Radical liberals do not realise that the commodity itself is the building block of class ruled society. As history of human social relations has demonstrated, the commodity undermines any attempt to maintain equal political power between all men and women.
""We all rail against class distinctions, but very few people seriously want to abolish them. Here you come upon the important fact that every revolutionary opinion draws part of its strength from a secret convictions that nothing can be changed....So long as it is merely wishing class-distinction away. More exactly, it is necessarily that nothing can be changed...So long as it is merely a question of ameliorating the worker's lot, every decent person is agreed...But unfortunately you get no further by wishing class distinction away. More exactly, it is necessarily to wish them away, but your wish has no efficacy unless you grasp what it involves. The fact that has got to be faced is that to abolish class distinctions means abolishing a part of yourself. Here I am. a typical member of the middle class. It is easy to say that I want to get rid of class distinctions, but nearly everything I think and do is a result of class distinctions...I have go to alter myself so completely that at the end I should hardly be recognizable as the same person." - George Orwell
Capital, the modern form of class rule, is founded on wage labour. What is necessary to abolish classes is the abolition of the foundation upon which they are produced. I don't think Orwell grasped this; but he was touching on a fundamental aspect of the radical liberals' angst vis a vis abolishing class rule i.e. their own position in the hire-archy of Capital. I mean, a liberal who is well paid for her labour power is reluctant to embrace the notion that all labour is interdependent in the creation of wealth. Without the garbage man, the surgeon cannot find a clean hospital to do her work. But the surgeon is loathe to embrace the notion that quantity of her hours of labour should draw the same amount from society's collectively produced wealth as the garbage man's.
"Political economy--despite its worldly and wanton appearance--is a
true moral science, the most moral of all the sciences. Self-denial,
the denial of life and of all human needs, is its cardinal doctrine.
The less you eat, drink and read books; the less you go to the
theatre, the dance-hall, the public-house; the less you think, love,
theorize, sing, paint, fence, etc, the more you save--the greater
becomes your treasure which neither moths nor dust will devour--your
capital. The less you are, the more you have; the less you express
your own life, the greater is your alienated life--the greater is the
store of your estranged being."
(Karl Marx, Economic and Philosophical Manuscripts of 1844)