Tuesday, January 27 1998; Page A16

PRESIDENT CLINTON reportedly will urge in tonight's State of the Union address that, for now at least, any budget surplus be used to shore up the financing of the Social Security system. It's a good idea. As a practical matter, at least in the short run, it means using any surplus that may develop to pay down the national debt, rather than dissipating it in a tax cut or spending increase.

Paying down the debt would help solve the long-term Social Security problem in two respects. It would constitute an increase in national savings. The savings would lead to greater investment, the investment to greater economic growth and a larger economy. The larger the economy, the easier it will be to support Social Security in the future. By reducing debt now, the government also leaves itself more room to increase borrowing in the future when the baby boomers will retire and current revenues will be inadequate to pay current benefits.

The added, political, virtue of the idea is that it should help avert a tax cut. Republicans want to grant one. The president himself suggested on a couple of past occasions that he might be open to the idea. But in the face of the costs that the government can already clearly foresee when the boomers begin to collect more in benefits even as, having retired, they also pay less in taxes, a tax cut would be the height of folly.

It's hard to say no to a tax cut in an election year in the name of a remote concept such as debt reduction. It's a lot easier to do so in the name of saving Social Security. That's what the president seems about to suggest -- and in fact he would be starting the country down part of the path to save the program. It's not just a trick of vocabulary.

The sequester would have the effect of fending off possible spending increases as well. Some spending increases -- public-sector investments in such things as transportation, for example -- might themselves be defensible uses of a surplus, assuming one in fact develops. But there are other ways to finance them if they are deemed desirable.

Ultimately, the saving of Social Security together with its companion Medicare will require additional discipline in the form of benefit cuts and tax increases. But it will require, or be made easier by, increased savings as well. Whatever else Congress does tonight, this is one idea that both parties should applaud -- and then adopt.