Can anyone help interpret this section of Marx’s writing?

From The German Ideology, it’s placed in footnote 2, here [some explanatory context to hopefully help make more sense of it appears below]

Just because the individuals seek only their particular interest,which for them does not coincide with their communal interest (in fact the general is the illusory form of communal life), the latter will be imposed on them as an interest “alien” to them, and “independent” of them as an in its turn a particular, “general” interest; or they themselves must remain within this discord, as in democracy.

According to the edition of this book that I’m reading [I’m not actually using the Marxists.org for close reading at the moment], this is part of a note in the margins that was actually written by Engels. In my edition of the book, it’s actually been placed in the main text, not as a footnote. In any case, it’s confusing me.

I think I’ve got the general gist of the argument that Marx made to get this far. We’re dealing with three kinds of “interest” here.

Once society develops to the point of the division of labour (argues Marx), then individual people can have individual ‘interests’, interests which are specific to their particular position within a society. This only occurs because people no longer engage in exactly the same kinds of work and receive exactly the same kinds of products. There is still at this stage of society a ‘communal’ interest, which Marx describes as “the mutual interdependence of the individuals among whom the labour is divided”.

The general interest is something different. For one thing, it’s not a real interest. At this point in Marx’s telling of history ,the State, although it “develops from the community”, exists independently from it, and is “divorced from the real interests of individual and community”. The state claims to represent the ‘general’ interest, but in actual fact it represents the particular interests of one class of society. All the apparently important specific political issues fought out concerning the nature of the State and of State power, at their core, nothing more than a struggle between the differently-situated groups of individuals within society to ensure that their ‘individual’ interests are accepted as ‘general interests’.

The bit by Engels above seems like an attempt to clarify this, but it seems to obscure the issue more than anything else. Is he trying to clarify the relationships between ‘individual’, ‘communal’, and ‘general’ interests? What is he referring to when he mentions “discord” and “democracy”? Should I even be bothering with this bit of obscurantism? It’s not like I haven’t got much more pressing tasks to do….

I do think at least a passing stab at Marx may be helpful for me to contextualise writings that are more directly related to my field of communications technology. Daniel Bell (post-industrial society), Manuel Castells (network society) and even Mark Poster to an extent (the mode of information) draw on his work. But it would help significantly make my time devoted to Marx more productive [heh] if someone could explain what the bloody hell Engels is on about here.