I would be willing to bet him that within the decade, it will become a mainstream idea in the progressive community to fund shortfalls in Social Security and Medicare with a full or partial seizure of 401K's.
This is not quite there, but it sure shows that they are thinking in this direction
The senior administration official said that wealthy taxpayers can currently “accumulate many millions of dollars in these accounts, substantially more than is needed to fund reasonable levels of retirement saving.”
Under the plan, a taxpayer’s tax-preferred retirement account, like an IRA, could not finance more than $205,000 per year of retirement – or right around $3 million this year.
Wealth taxes on large pools of savings are not far behind