By making the middle class pay more into Social Security. Or forcibly collectivizing retirement savings into government-run pension plans. With special extra mandatory savings.
(Wait, hasn't that idea been bouncing around Sacramento lately? Force most private-sector workers to pay into CALPERS, ostensibly so their retirement will be taken care of, but mainly as a temporary bailout for the underfunded government pension plan?)
Here's the thing: the past couple of decades, this country has had a severe case of malinvestment. And: it isn't the little guys, with their own money, doing it. Large-scale malinvestment happens when you have a small number of fund managers deciding how to invest vast amounts of other people's wealth, with an incentive system that separates risk from reward. (See also: CALPERS investing in the big Sand Hill Road venture-capital firms. And losing. Further: politically-motivated investment decisions based on social engineering rather than sound money management.)
Officially abolishing private investment decisions and handing everything over to the same damn idiots who brought us the dot-com bubble, the subprime-mortgage bubble, the insolvent state pension funds, and negative real returns on Treasury bills... yeah, that's great public policy.
And then there's this: I haven't been able to save anything toward my retirement lately - even if there were any positive-return investments available to non-insiders - because I don't have the money available. If the Feds weren't "borrowing" (at a negative real interest rate) sixteen-point-mumble percent of every damn dollar I earn, I'd have cash available for investing in stocks, building up my own business, or otherwise making preparations for a better future.
And I'd be making my own decisions, with my own little bit of money. If I screw up my retirement planning, it affects me and a few other people. If the central planners screw up....