Shut down 90% of the US banking system and the federal government immediately. Make having more than 1 chequing account and 1 credit card illegal.
Take all of the resources that were consumed by the banking system and direct them towards US Citizen engineers, to rebuild all of the manufacturing and energy infrastructure that has been neglected, destroyed, or under-invested in, during the past 30-40 years. Tell the Chinese, "thank you very much, but we're going to be self-sufficient now."
A fundamentally sound economy would have no problem whatsoever supporting its elderly, generating capital for re-investment, etc.
No amount of financial engineering, taxation changes, etc., will fix the underlying problem in Social Security, and that is, it requires massive increases in per worker productivity, in order to sustain itself.
The solution is right under everyone's noses. It might be painful for the 'money for nothing' crowd, but it will definitely restore the equity and dignity to hard-working and bright US engineers who have been completely disenfranchised in the past few decades by the money men.