I'm not sure what this is apropos of, but you've invited me to try out another of my harebrained ideas on you, so brace yourself.
I would propose that working class be defined as those whose sale of labor services from ages 20 to 65 (whether they do so or not) can afford them an average annual consumption level no better than some percentile in the range of 60 to 80. So I would include the poor, ANY type of sub- supervisory worker, and self-employed/proprietors with not too much capital.
So someone who builds up a large stake by abstaining religiously from consumption could still be working class, his/her wealth notwithstanding.
The basic idea is to distinguish in a systematic way in terms of lifetime income, irrespective of personal choices regarding saving, and to ignore ersatz distinctions between production workers, service workers, petty supervisors, self-employed, mom-and-pop owners, and cops. In other words, to take the working class in its actual, integrated social form, rather than trying to force it into an ill-fitting abstract category.
The class in this sense remains the historic source of social progress, in my view, with an addendum or two required to acknowledge some professional and student movements, some of whose participants would fall outside my income definition. In this view, ownership of capital or "relation to the means of production" per se is not as magical as made out by some. I would say lifetime income and its underlying factors say more about a person's outlook than some more rigid definitions of class. I acknowledge that there would be a question of dynamics here, as the factors underlying class by any definition are mutable.
The connection to identity politics is that minorities and gender per se is not subsumed by class but overlaps it imperfectly. The conceit of identity politics is that race, gender, or sex is prior to or supercedes or "constructs" class.
The issue is not whether race or gender divides the working class, but what sort of identification (class or other) is fundamental to a successful, meaning majoritarian, politics. The first premise of ID Politics, for all practical purposes, is a moral rebuke to white males, usually from disengaged academics or separatist formations. The first premise of class-based politics is a universal appeal regarding living standards and the universal rights of humanity. Working out the family feuds is only made possible, I think, after gathering all within a big tent.
Statements about race and sex, however erudite, contained within academic settings, which have no political correlate (liberal, radical, or revolutionary) are not politics. Practicality is not the issue here, as it is in the endless reform versus revolution debates, but existence itself.
It may be arrogant to say so, but I don't think an understanding of POMO theory (which I do not claim) is germane. Regardless of whether anyone thinks I'm an activist or not, and regardless of what politics I like and what I don't, I can SEE the political scene, both nationally and locally. I can see radical groups with whom I disagree and others I like more, I can see the grassroots activity, and I don't see POMO anywhere. I see yammering on campuses and unreadable texts in academic journals whose principal effect is distraction and the waylaying of potentially useful radical students into political dead ends.
MBS