Interesting! I didn't know there were different distinctions.
Still, I think your source really just proves my point: by no means is anyone earning 120K a year "solidly middle class". By pretty much all of the definitions you listed, 120K a year would either be "upper middle class", or "the rich" (e.g. find me a homeowner in SF who doesn't have >1 million in home equity).
Still, I think your source really just proves my point: by no means is anyone earning 120K a year "solidly middle class". By pretty much all of the definitions you listed, 120K a year would either be "upper middle class", or "the rich" (e.g. find me a homeowner in SF who doesn't have >1 million in home equity).