THE NATIONAL drive now under way for a constitutional amendment requiring a balanced federal budget is not unique. There have been similar efforts by state legislatures in the past to amend the Constitution in one way or another by means of a constitutional convention. What's different about this one is that is seems to be getting perilously close to the point at which Congress may have to act, either by calling a convention or drafting an amendment itself; 26 of the necessary 34 states have approved convention calls. We say perilously because we think this is a bad idea, for many of the reasons set forth in a series of articles on the opposite page on Monday, Wednesday and Friday of last week, attempting to put the issue into some sort of legal and historical perspective. When the issue is subjected to that sort of analysis, as distinct from a discussion on the virtues of a balanced budget, it seems clear to us that the first and perhaps conclusive test of any such amendment to the Constitution has to be what it would mean for the Constitution itself.

So we would set aside for now the question of what a budget-balancing amendment of any kind would do to the ability of the federal government to deal with the economic well-being of the country -- the short answer to that question, in our view, is that the budget-balancing amendments, in their simplest forms, would wreak economic havoc. As for the more complex formulations now being advanced -- the ones designed to give the federal government a little more economic flexibility -- we think they would wreak constitutional havoc. And we would take as Exhibit A the proposal of Nobel Prize-winning economist Milton Friedman and the Committee on National Tax Limitation. Its sophisticated escape clauses may make it an economist's dream. But it is a constitutionist's nightmare. The Constitution is beautifully written, phrased in succinct and clear language, so broad in its meaning -- and possessed of just the right measure of essential ambiguity -- that most of it has survived intact for almost 200 years. Compare its language, if you will, with just one passage from the Friedman amendment:

Ttotal outlays in any fiscal year shall increase by a percentage no greater than the percentage increase in nominal gross national product in the last calendar year ending prior to the beginning of said fiscal year. If inflation for that calendar year is more than three percent, the permissible percentage increase in total outlays shall be reduced by one-fourth of the excess of inflation over three percent. Inflation shall be measured by the difference between the percentage increase in nominal gross national product and the percentage increase in real gross national product .

Hardly the work of James Madison or Benjamin Franklin, would you not agree? It was Madison who argued against one provision proposed at Philadelphia in 1787 because the public would never understand it. And it is hardly the kind of material John Marshall was referring to when he wrote, "... we must never forget, that it is a constitution we are expounding," a constitution "intended to endure for ages to come."

The authors of the Constitution used only three words to give Congress the ultimate power a government holds -- "to declare war" -- and only 16 to give it control over interstate and foreign commerce. They needed only 429 words to describe almost all of the vast powers given to Congress. The authors of this budget-balancing amendment have used 476 words to say Congress must balance the budget. Their amendment, in fact, is longer than the entire Bill of Rights.

Reflect on some of the terms used in the proposed amendment. "Gross national product" is an inexact accounting statistic, devised by economists as a tool to measure the goods and services produced by a nation's workers.The initial figure reported for any year is subject to revision as additional data are collected. It is influenced not only by business conditions in this country, but also by such things as the nationalization of American-owned property abroad. Its meaning may be clear to economists, but what about the judges and lawyers who would be required -- presumably for the next 200 years -- to translate it into specific numbers? Due process of law, equal protection, freedom of speech -- these are matters of high principle, appropriate to a constitution. "Gross national product" and "inflation" -- these are the necessarily arbitrary and imprecise mathematical calculations of economists, appropriate to the president's annual economic report.

There is more that can be said about what this particular amendment would do to the Constitution. It would be the first part of the Constitution that would authorize members of Congress to file suit in federal court to enforce its terms; it even names the specific court in which the suit would be filed -- a court whose existence is not even acknowledged in the original Constitution. It would also be the first part of the Constitution that could be altered by a system other than the adoption of an amendment; it would provide that the "limit on total outlays" could be changed by a three-fourths vote of Congress, if approved by a majority of the state legislatures.

Leaving aside the compelling point that the Congress right now has all the authority it needs to impose a balanced budget by the appropriation process, this version of the proposed budget-balancing amendment is so at odds with the principles on which constitutions are written that it should be rejected out-of-hand by even the most ardent budget-balancers. The document it would amend is not some municipal code or even a piece of national legislation. It is the Constitution of the United States of America, and it deserves to be treated with some respect.