Even with QE, US now spending 26% of (true) available tax revenue just to pay interest

``The IRS collected $2.49 trillion in taxes last year (net of refunds). But of this amount, $891 billion was from payroll tax. According to FICA and the Social Security Act of 1935, however, this amount is tied directly to funding Social Security and Medicare. It is not to be used for interest payments. Based on this data, the amount of tax revenue that the US government had available to pay for its operations was $1.599 trillion in FY2013.... approximately 26% of their available tax revenue just to pay interest last year... a much higher number than 17% [claimed]"