The balanced budget amendment signals a breakdown of ordinary political will and discipline, as even the amendment's firmest advocates admit. It means that economic doctrine--the sanctity of balanced budgets and the capping of revenues at a certain fixed level of gross national product--may be written into the Constitution, the nation's basic social compact, and there occupy the same exalted status as free speech and due process of law.

Historically (and this is perhaps one reason why Ronald Reagan has embraced the amendment), the balanced-budget measure would reverse the most fundamental of New Deal constitutional doctrines. This is the doctrine that the Constitution does not chain the nation to any economic orthodoxy. Whether or not the Constitution establishes an economic orthodoxy was the great issue between Franklin D. Roosevelt and "the horse-and-buggy" Supreme Court majority of the mid-1930s. The question was whether the Framers' handiwork not only guarantees a republican form of government and the ideologically neutral rules and forms essential to it, but also mandates certain economic arrangements: say, a certain relationship between management and labor.

FDR, though he lost the "court-packing" fight in 1937, won the war. From that day onward no judge presumed to discover his own economic prejudices engraved in the organic law of the land.

The balanced-budget doctrine, like the companion doctrine that a specific level of public-sector spending (say 20 percent of GNP) is appropriate, raises issues of policy. These are prudential issues, arousing strenuous disagreement, but properly to be settled in the political arena without fear that the triumph of one view or another would undermine the American system of government. Once economic doctrines are written into the Constitution, however, they cease to be issues of policy. They become fixtures of law which judges are sworn to enforce.

In a background paper of July 26, the White House Office of Policy Information argues that this is no novelty: "The wisdom of addressing economic matters in the Constitution . . . is a false issue." The Constitution, insists the White House, already deals with taxing and appropriations powers, state tariffs and duties, and the coinage of money. So it does. But there is a difference. The foregoing provisions, one and all, affect the structure of American government and the arrangement of powers among its branches. They establish no economic orthodoxy. State tariffs, for instance, were not forbidden because the Framers disliked protectionism and wished to entrench free trade as eternal constitutional doctrine. They were forbidden because placing the discretion to levy tariffs in state hands might disrupt the national customs union which it was one aim of the Constitution to establish.

The ultimate irony of the budget-balancing amendment is that it may compound the dilemmas of Congress. By one preliminary congressional staff estimate, the amendment, if in place by 1985, will require a $70 billion to $80 billion cut for that fiscal year in discretionary spending beyond the level contemplated in this year's first budget resolution--if, that is, economic performance matches optimistic expectations.

One can argue that the amendment is needed precisely because such cuts are needed, and yet have proved to be beyond the will and wit of Congress. But Congress, weary to death of the intractability of the federal deficit, should have no illusion that it is making itself a bed of roses. Your real troubles, it has been well said, begin when you get what you want.