In a nutshell

This is what I call clear thinking.

The main economic consequence of privatization is that it eliminates the need for income taxpayers -- primarily rich people, that is -- to pay higher taxes in the future in order to repay the loan they were granted by working- and middle-class Americans in the 1980s and 1990s.

The pronoun "they" refers to "taxpayers," although the verb "repay" does not refer to the same individual "taxpayers." The repayment will also never - repeat: never - repay the actual people who involuntarily "granted" that "loan," because most of us (Yep, US) will never receive repayment. Those pre-inflation dollars, taken from day one of earnings, were worth a lot more at the time they were earned than they are coming back in the form of Social Security checks.

This sentence recognizes and admits that it is "rich people" who do, in fact, pay most of the income tax.

But it also underscores the fact that SS "contributions" collected from "working- and middle-class Americans" start vanishing from their earnings with the first dollar, and continue, with no deductions, unless and until they hit the annual cap on contributions. This feature of the Social Security system has been at the foundation from the start. The soundness of the system, the reason that it has survived so long, recalls that old saw by Lincoln that God must have loved the common man because he made so many of them.

Individually, working people are not known as "rich," but collectively, as in the unhappy example of state lotteries, the money collected from them adds up in a big way. (Somebody looked at a stringer of tiny little fish proudly showed off after an afternoon of fishing, and said, "You aren't going to eat those little things, are you?" The kid replied, "I guess we will...we eat butterbeans, don't we?")

[An afterthought: Don't you just love that word contributions?]