The Concord Coalition has published A "One Percent" Tax Increase Will Not Fix Social Security’s Problems. Here is the Introduction:

The Social Security payroll tax . . . is now levied at a rate of 12.4% on workers’ earnings up to $90,000 a year. Employees and employers split the tax, meaning that they nominally pay 6.2% each. The Social Security trustees now project that the program has a deficit over the next 75 years equal to 1.89% of the payrolls on which the tax is levied (taxable payroll). Various commentators have thus pointed out that, in theory, the entire shortfall could be eliminated by levying a tax increase of a little less than 1% on employees and employers each (bringing the combined tax rate up from 12.4% to 14.29%.

What then is all the fuss about? If employees and employers each simply paid 1% more, the problem goes away…Right? Wrong. The 1.89% deficit figure is a highly misleading measure of Social Security’s funding shortfall. Ultimately, a tax hike at least three times as large would be required to pay scheduled benefits.