Romney's was in a regular IRA. He delayed taxes. Withdrawals are taxable as regular income. If he was really smart, he would have done it outside his IRA and paid the taxes on the lower capital gains rate.
https://en.wikipedia.org/wiki/401(k)#History :
"Congress [... enacted the ...] Internal Revenue Code Section 401(k) as part of the Revenue Act.[8] This occurred on November 6, 1978."
Perhaps we could cut back on entitlements , too. That would bring bigger savings and help with the governmental fiscal responsibility thing. Lower debt would let people keep more of their money to spend on making their lives better.