Some Social Security Math.
Just a point of reference for understanding what is reasonable in the discussing Social Security reform: under the present system, consider a person enters the workforce at 25, with a starting yearly income of $20K, an annual raise of 5% (inflation + merit), and an employee+employer deduction for Social Security of 12.4%, using the current cap of $106,800. Upon retirement at 65 the citizen will have a personal savings of about $290K. The retiree living to 85 will then have a monthly income from this savings of about $1210.
Now, allow this stagnant savings be partially invested (like the federal employee program) such that it results in an annual return of just 2%. The personal savings after forty years will be $390K, for a monthly income (assuming no additional growth) of $1625, more than 30% higher than the stagnant system. Assuming a 1% return on the savings will result in a personal savings of $335K. Of course, these calculations assume that the government didn't spend the money on something else, i.e., they didn't steal it.