What I would like to know is, how much of this income from the earlier data is coming from single paycheck households compared to the double paycheck households prevelant today? I have no doubt the Times is playing loose with figures to promote their agenda, but there's an underlying problem here that many seem to overlook.
It seems that it used to be much easier to achieve Middle-Class on one paycheck than it is now. You technically end up with people working twice as hard for the same amount of money.
Your definition of Middle Class is so unfocused as to be practically meaningless.