Commenter "Thena, Sultana of Stale Raisin Bread" addresses the difference between poor, working class and middle class:
The difference (IMO) between working-class and middle-class is not just about income but about security.
I figure it this way:
the genuinely poor are those who struggle to get by on a day to day, week to week basis. The keyword here is Survival.
the working class (where I see myself) are those who get by but can’t really get ahead - able to pay the rent but not save up enough for a down payment, perhaps, or employed but uninsured, for instance. The keyword here is Security.
Real middle-class status, to me, implies a certain basic level of security: you know you’ve got enough to take a hit and keep rolling in a “One down three engines good” sort of way. You own your home (or have a mortgage that you can easily keep up with); you have health insurance and savings and a 401K or a government pension and you can reasonably expect that things are going to be Okay - maybe not fabulous, maybe you won’t make that trip to DisneyVille this summer, but you’ll eat regularly and go straight to the ER when you injure yourself instead of waiting a few days to see if it gets better on its own. The keyword here is Stability.
(In this paradigm I’d use “Savings” as the keyword for the upper class - being those who have money left over to save or invest after their material needs and comforts are assured for the foreseeable future - and “Surfeit” as the keyword for the genuinely wealthy, the people who have more money than I can figure out what to do with. And I am capable of finding good homes for absurdly large dollar figures, I work in a state government accounting office. At the moment.)
By this measure I believe there are a whole lot of people in this country who are not middle class but call themselves by that name because they don’t want to admit the economy’s broken.
(In case you were wondering about the name: there was a period where most regular posters at Pandagon had a food-related nickname, or a foody variant on their normal nickname. Why, I cannot recall.)