This is based on a report (linked below.)
The whole idea is various incentives and business practices that have changed whom based on income level (and how those that do) save for retirement.
The conclusion of the report suggests this condition is not because of "natural" economic function, but rather imbalanced and disproportional regulation and tax code. So it is less about "the poor spending more then they save" as a economic behavior fault but rather problematic economic distortions.
For instance. One distortion mentioned (and happens to the top action item mentioned in the conclusion) is dealing with unlimited savings tax deferral ability for those generally at the top income quintile (like CEOs,) but seeing corporate 401Ks limit employee contributions to their retirement plans. Some of that is a practical matter as the lower we go down the income quintile the bigger the percentage of that income is immediately needed for living. But, there are things the report suggests on capping tax deferral ability for the top income quintile. Not sure I completely agree with the idea but I get the thinking on trying to even the playing field, even if it means another distortion and probable consequences.
One item I do agree with is linking corporate tax benefit to the offering of retirement plans, of course the inverse being taking away various tax incentives when a corporation does not offer various means of retirement savings.
But another problematic area is the suggestion of State ran pension plans for the private sector. It would make private sector plans function like public sector union retirement plans, and ultimately shift how much liability was extended outward to future contributors. Effectively, a bunch of Social Security Trust fund like plans ran by the various States and with funding levels dependent on fiscal controls State to State.
Any "expansion to Social Security" ends up limited to taxation on the higher income quintiles. I am not convinced that taxing wealth even more really solves the problem.
Review for yourself...
http://foreffectivegov.org/files/two-retirements.pdf