IS THE NONSENSE quotient rising as the number of presidential candidate debates increases? Certainly it's not falling. The most recent evidence came in the two debates sponsored by the Atlanta Journal and Constitution last weekend. Whenever the subject turned to the federal budget deficit, or to taxes, or to the economic future of the nation, candidates of both parties moaned and groaned loudly about the Reagan budget deficits. But none dares to say in plain words what almost every voter knows must be done if the deficits are to be gotten down to tolerable levels: raise t----.

So from George Bush you will hear brave words about the deficit's being "public enemy No. 1." But if the G-men went after Alvin Karpis with Tommy guns, the vice president goes after the deficit with the popgun remedies of spending cuts and a line-item veto. You won't see forthcoming from him, any more than from Mr. Reagan, a list of spending cuts or veto-worthy line items that add up to any number close to the deficit. Jack Kemp, as Bob Dole aptly put it, "has never met a deficit he didn't like," and as a cure for the administration's overly generous tax cuts promises more of the same, plus "a dollar as good as gold." Mr. Dole, whose impressive legislative achievements include the 1982 tax bill, was busy in Atlanta arguing he is the biggest tax cutter of them all, armed with a printout of the spending and tax bills he's voted against since 1975. Pat Robertson finds the problem "a question of will" and cites his success in cutting the Christian Broadcasting Network budget one year.

As for the Democrats, Michael Dukakis bravely criticized Richard Gephardt's vote for the 1981 Reagan tax cuts, which he blamed rightly for the elephant-sized problems of budget deficits, trade deficits and loopholes for the wealthy. His solution, however, is mouse-sized: tighten up on the supposedly $110 billion of taxes that go unpaid. Stricter enforcement is a good idea, but to suggest that anything like the sums he talks about could be recovered is either demagogic or -- worse -- delusionary. As for Mr. Gephardt, his solutions are things like an oil-import fee and farm production controls -- whose main effect would be to shift some spending from the federal government to consumers. Albert Gore offers little more than "leadership" on these issues and Jesse Jackson little more than the promise of deep defense cuts.

The temptation is to throw up one's hands and say it doesn't matter; the deficit commission next year will force the new president to do something intelligent no matter how many stupid things he's been saying on the campaign trail. But campaign rhetoric does have consequences; it tends to constrain choices, to choke off alternatives, to get successful candidates painted into corners from which they cannot move except at heavy political cost. Maybe it's too much to expect the candidates to say sensible things about this problem. Is it too much to ask them not to talk nonsense about it?