Yes, although I think we should be skeptical of basing our movement on the lumpen. As Marx and Engels point out, the lumpen can be quite easily bribed by the ruling classes and doesn’t really form a solid revolutionary movement. But classes like colonized people and black people in the US have already historically been involved in vanguard formation (e.g. the Black Panthers), and even today we see genuine movements popping up which are led by these classes (e.g. Stop cop city, and even things like the Amazon union led by Chris Smalls). The patsocs disregard (or even attack in the case of land back) all this and instead choose to pander to reactionary white sections of the population whose revolutionary potential is non existent.

To circle back a bit to the purity discussion, today I found this great pamphlet by Lenin in which he talks about factionalism and I think that discussion nicely mirrors the purity discussion and responds to MWM’s position (which despite what they claim boils down to “everyone in unpure except us”).