The Democrats have been mostly coy in responding to President Bush’s plea to create private retirement accounts as part of Social Security. For the most part, they have opposed the proposal without offering any ideas of their own about how to pay for the projected future shortfalls in the system. Sure, Peter Orszag of the Brookings Institution has put forth a plan, more or less endorsed by the New York Times, to raise the Social Security payroll tax rate over time to 14.2% from the current 12.4%. But it isn’t as if Democratic politicians are out openly campaigning for that kind of tax increase.

So it’s illuminating to turn to the March-April issue of Harvard Magazine and see a cover story by Jeffrey Liebman, a professor at Harvard’s Kennedy School of government who served as special assistant to President Clinton for economic policy. Mr. Liebman, interestingly enough, advises Democrats to abandon their traditional opposition and instead, “embrace personal retirement accounts.”

Progress? Well, yes and no. Mr. Liebman’s reason for opposing an increase in the Social Security tax is that “we need to save the tax increases for Medicare and Medicaid.” He predicts, “Over the next century, the share of national income that we will want to devote to healthcare will likely rise substantially and, because much of healthcare in the United States is paid for by the public sector, we will need to increase tax rates substantially to cover those costs.” So under this approach, the Democrats still favor tax increases – just to fund health care instead of pensions.

And, while Mr. Liebman denies he is for a Social Security tax increase, his model of personal retirement accounts looks a lot like a tax increase. He says he doesn’t want to turn any of the existing 12.4% payroll tax over to private accounts. In stead, he said, the personal accounts should be a 3 percentage-point add-on – bringing the total pension cost to 15.4% of payroll.

It’s all enough to explain why the Democrats have been so reluctant to offer any proposals of their own on Social Security. Even the ones who say they don’t favor tax increases have nothing to offer but tax increases. It may be that the best argument Mr. Bush has on this issue with the voters and with Republicans in Congress is, “We’d better fix this problem now while the Republicans are in control, because if the Democrats get their hands on it, their solution is going to be a big tax increase.”