I do believe that's the
'Old Left'/
'New Left' divide. The Old Left were
actual working class socialists and commies, people like the West Virginian & Coloradan miners who fought running battles against management, police and even the National Guard from time to time, and generally couldn't give less of a flying crap about gay rights, abortion or whatever while focusing wholly or almost entirely on the economic side of things - worker ownership of the 'means of production', mass unionization, etc. While the New Left are the 'coalition of the margins'. They're the seething terminally online ancoms, deconstructionist academics, child rapists, genderspecials who want their pronouns respected on pain of death, racial supremacists who unironically think Cleopatra and Hannibal were black, other minorities with a chip on their shoulder the size of Texas (like the Umair Haque whose articles cropped up in this thread), and generally psychopathic nihilists who desperately want to destroy everything to fill the ravening void within where their souls used to be, all unified only by their overwhelming hatred of the cis-hetero patriarchy and basically everything good and sane in the world.
My understanding is that in the States, this divide got going in the '60s with the ascendancy of the hippies, the civil rights movement and people like
Herbert Marcuse. But the divide always crops up everywhere a left-wing movement gets big enough, and especially wherever they manage to take power, and has its different names all over the world. ('Orthodox' Maoists vs. Dengists in China, for example.)
Also, the New Left tends to be so much more unbearable to live with (much less live under) that they inevitably piss off literally everyone around them and get purged by the Old Leftists at the earliest convenience. Hence Stalin purging the Old Bolsheviks after Lenin died, Deng Xiaoping purging the Gang of Four after Mao died, and the slightly saner (formerly North) Vietnamese routing the Khmer Rouge after 'Nam. Can't blame them for that tbh, as someone who hangs out anonymously on a Discord overrun with New Left types that think the Black Panthers and Weather Underground were only wrong because they didn't overthrow the US, I can safely say that literally anything would be better than the nightmare these lunatics want to force on everyone else and that any tactic would be justified to keep these 'no bad tactics, only bad targets' types out of power.
Unfortunately the Old Leftists tend to be sane enough that they're able to put together still-horrible societies which manage to function for at least the average citizen's lifetime, as well, instead of one that manages to speedrun postmodernist horrors before burning out relatively quickly. The Soviet Union Stalin built managing to last to 1991, instead of attacking the rest of the planet and promptly getting roflstomped into the Siberian dirt by 1930 like Comrade 'World Revolution' Trotsky would've wanted, is just the most obvious example.