With congressional election campaigns in full roar, Terence McAuliffe, chairman of the Democratic National Committee, this year sent out fund-raising letters charging Republicans with plans to dismantle our Social Security system. As I see it, McAuliffe is guilty of mail fraud. First, the letters imply that the plan requires most, if not all, Social Security tax revenues to be invested in stocks. This is false. Under the Bush plan no taxpayer is required to invest any revenues in the stock market. The investment is entirely voluntary and is limited to no more than 16 percent of the payroll tax....