The problem is that doing so has the rather unfortunate side effect of basically just erasing rural minorities from the conversation entirely. I sympathize with your aversion, but honestly I think that using "working class" as a synecdoche for "white working class" is pretty much just the worst possible option here.
Firstly,
which conversation? What I was trying to do was to point out that there are
multiple conversations (or 'issues' or 'debates'... the word isn't important, so long as we all know what we mean) here; I would now like to argue that one cause of the sort of marginalisation you're (quite rightly) concerned about is the tendency to confuse them. So we have:
1) The fact (as I see it anyway) that urban progressive liberals have only ever been interested in 'rural America' (wherever that place may in fact be) in an abstract and idealised - or abstract and cartoonishly mocked. Don't worry
too much about that; rural people world over do the same unto thee - sense. These worlds don't really mix and aren't particularly relevant to each other. The attitudes of America's urban progressives to 'rural America' are only of importance to America's urban progressives and how they see their country.
2) The fact that the Democratic Party is actually pretty strong in large parts of America that could be described as 'rural'. This is mostly down to the support of minorities, but there are also white rural areas where the party remains strong, and these are frequently not-at-all impoverished. Prosperous agricultural districts in much of the Upper Midwest and so on. Writing out minorities from this discussion would be reprehensible, because they're central to it.
3) We then have the collapse of the Democratic Party in most provincial industrial and postindustrial areas (including rural-industrial areas in the - particularly upland, and thus white - South, of which there are considerably more than is often remembered), which is one of the most striking electoral facts of our time. There's a tendency to think of most of the relevant places as being rural (as if an industrial town of 20,000 or whatever is rural;
absurd) because of the odd status of cities in the American imagination (or so I'd argue), and from this we get some of that very unhelpful confusion.
In the last of this 'conversations', minorities are as basically irrelevant every bit as much as they are basically central to the second 'conversation'. I don't think racialising the language serves any useful purpose, and I think that (urgh) 'white working class' as a phrase has only negative results on discourse. Isn't it curious that no one ever writes 'white middle class' or 'white bourgeoisie' or whatever? Mind you, I'll confess to a lack of sensitivity on the nuances of racialised language (when it is to be used, when not, how it is to be used...) and so on in American English, but then that's hardly my fault...
