Katharine, Lyndon Johnson's original sell of Social Security was that it was more an individual retirement fund (admittedly government enforced) than an entitlement. The logic of the cap was that once folk had paid sufficient, they could be excused from paying more (its private frame).

Gradually increasing the qualifying age makes sense (as Macron is trying in France).

Multiplying the immigration numbers into the U.S. is another way to get more funding into the program.

Many thanks. Best