Robert Weissberg details here the older definition of what it meant to be middle class, you know, the one which is now politically incorrect to talk about, let alone be:
The core of being middle class was a strong work ethic, self-discipline, a willingness to defer gratification, an aversion for flashy consumption, and an embrace of what might be called “respectability,” (i.e., sobriety), a morality that stressed honesty, a solid family life, being law-abiding, and valuing education (though not necessarily being “intellectual”).
Inner dispositions were associated with speaking clear, grammatical English, exhibiting decent table manners, never using profanity in public (and almost none in private, too), being “clean cut” in appearances and always acting politely. Middle class members also abhorred the thought of taking government handouts. ...
These “square” traits were associated with material well-being but were really a result of middle class values, not its defining elements. Nobody believed that the causal flow was reversible—home ownership could inculcate middle-class values. In principle, it was possible to be lower class despite owning middle-class doodads. A well-paid entertainer may live well but could still be considered white trash if he dressed in tattered clothing, beat his wife, openly philandered, cursed and spit in public and spent a dime for every nickel earned.