Congress spent these surpluses, and the U.S. Treasury issued the Social Security Trust Fund special bonds, which can be redeemed whenever the Social Security system has a current account deficit.

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However, Heritage would go in the opposite direction and repeal the payroll tax entirely and fund the (much smaller) Social Security system through the flat tax.

FORBES: Areas Of Agreement On Tackling The Budget Deficit

To make matters worse, a permanently temporary tax cut further damages the credibility of the Social Security system which the payroll levy is supposed to fund.

FORBES: Payroll Tax-Cut Deal: Borrowed Money, Borrowed Time

Conservative peer Lord Fowler, a former social security secretary who introduced the fund in the 1980s, said a system was needed "for dealing with emergency payments of one kind or another".

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