SPEAKER O'NEILL and the House Democratic leadership deserve praise for both political skill and political courage after the defeat Friday in the House of the constitutional amendment purporting to require a balanced budget. Mr. O'Neill predicted that 155 Democrats would vote against the measure -- enough to kill it, since a two-thirds vote is required to amend the Constitution. In fact, 187 congressmen, 167 of them Democrats, voted against it. That's pretty good vote-counting, and it shows that the House leadership, after getting licked on some big issues last year, has developed political skills not seen on that side of Capitol Hill for many years. Mr. O'Neill also used his scheduling prerogatives well, by bringing the measure forward quickly, when he had enough votes to beat it; the Republicans, who have been clamoring for a pre-election vote on this amendment for months now, are in no position to complain that he acted before Mr. Reagan had time to charm members into voting his way.

The conventional wisdom about the amendment is that, while it may very well be bad government, it's good politics: voters support a balanced budget by a wide margin, and therefore Democrats will suffer in November because it was beaten Friday. We disagree. We think the amendment is bad government and bad politics, too. The amendment promises something -- an automatic, quick-fix, sure-cure guarantee that the budget will always be balanced -- which is beyond the capacity of government to deliver. If it weren't, why does Mr. Reagan decline to promise a balanced budget even in what the experts call the "out years" of 1985 and 1986? In practice, the amendment would either hamstring government or it would be cynically evaded -- our guess would be some of both. Neither is good for government or the political process.

As for the 1982 elections, most of the Democrats who voted to kill the amendment are from safe seats and have no significant Republican opposition. Other Democratic candidates can ask Republicans why they haven't balanced the budget yet themselves. Republican strategists evidently hope to divert voters' attention from the state of the economy to Congress' rejection of the balanced budget amendment. But voters are more interested in getting long-term solutions to our economic problems than they are in any particular mechanism. They like the idea of a disciplined, balanced budget, but they also understand how it is literally ridiculous -- worthy of ridicule -- for a party that lacks the political will to balance a budget to claim that it has some mechanism that will automatically do that and seven other wonderful things, like those gadgets they used to sell on late-night TV movies. For the next five weeks of campaigning, voters will hear more about the balanced budget amendment, we are sure. But unless the Republicans can make some gains on this issue -- unless they can hang some scalps on the wall -- we expect to hear little of it next year. Congress can return instead to the difficult, real-world task of keeping government spending and revenues in reasonable balance.