ALIFORNIA GOV. Jerry Brown is better than most at elbowing his way to the front of a passing political parade. But Mr. Brown has outdone himself, and perhaps also done himself in, by leaping to lead what he sees as a coming crusade for a constitutional amendment to bar federal deficits -- and for a constitutional convention to advance such an amendment if Congress fails to act. By this opportunistic show, Mr. Brown has not only managed to plant himself somewhere to the right of Ronald Reagan. He has also dispelled any lingering suspicion, at least in our mind, that he might be fit for national leadership after all.

Precisely what is the budget-balancing banner that the governor wants to bring to Washington? It really isn't clear. Constitutional-convention calls have been approved, often with little though, by 22 states' legislatures (34 are required). Some of the resolutions mandate a balanced budget without defining one. Several say that congressional appropriations shall not normally exceed estimated revenues. That is a sure prescription for shameless overestimating of revenues and underfunding of such mandatory programs as unemployment compensation and military pensions.

When you back off from the language problems, though, the aim is very clear: to turn off what Mr. Brown called "this perverse government money machine" and make Washington live within its means, as the saying goes, except in times of war or congressionally certified national emergency. This is medicine so harsh as to raise questions about what it's meant to cure. As a practical matter, a balanced federal budget any time soon would require draconian cuts in both social programs and military spending -- or else (since there are two ways to balance budgets) tax increases of a most disruptive sort. Faced with those choices, Congress would probably duck by declaring an emergency, which would become perpetual.

Beyond those unwholesome effects, a balancedbudget amendment would lock into the Constitution the economic theology of the Hoover era and the 19th century. Federal spending could no longer be used to counteract recessionary forces, stimulate (or retard) the economy or otherwise provide stability. Those who see government as unresponsive now should contemplate what such rigidities could mean. And even Mr. Brown ought to appreciate the value of federal flexibility; there was at least a moment back in June when he was looking for more federal aid to ease the pain of Proposition 13.

We do not doubt that there is popular sentiment for the sort of panaceas Mr. Brown is proposing. People are genuinely concerned about inflation and big -- and unresponsive -- government. President Carter knows this, and is making at least a serious and responsible effort to deal with the problem. Mr. Brown is playing fast and loose with people's legitimate hopes and anxieties.