A national consensus of sorts seems to be forming about the presidential campaign. It is that both candidates are too busy attacking each other to have anything of real interest to say about how they would govern if they win.

What has caused this state of affairs? To begin with, some of the best people in both parties chose not to run.The two finalists in a lackluster field - George Bush and Michael S. Dukakis - have by and large gone on to conduct packaged drives aimed at selling themselves on television like some new beer or breakfast cereal. Within each party, they are the candidates of the lowest common denominator. As a result, quite a few thoughtful people have tuned out in disgust. At best, voters wonder why the hard choices that face the country aren't being addressed.

Imagine if either Bush or Dukakis were to stop worrying about how they came over on the little screen and were to speak out along these lines:

"We are now witness to the disintegration of the old order. We have stood for decades in defense of a free world. We have given as no other nation to the securing of world order and for it we have paid a heavy price on the ledger of neglect.

"This does not mean that the United States should abandon its international commitments. But it does mean that the first priority of the U.S. is our own nation. It's time to reach down and touch the troubled spirit of America.

"Black America and poor America are teaching us a new language. They say let us share in your prosperity, let us not have another generation of servitude, but a new generation of opportunity."

There's only one politician on the national scene who might give such a speech - Jesse Jackson - and look what's happened to him. Dukakis might consider it - until advisers jogged him back to the reality of avoiding, at all costs, appearing soft on national security. For George Bush to speak in such a fashion would be viewed as an act of sheer political lunacy and, for the hard right, of heresy as well.

As it happens, those words were said by Dan Evans, the former governor of Washington and once a rising star in the GOP. They were said in the keynote address to the 1968 Republican National Convention in Miami Beach. But the delegates discarded Evans' advice and nominated Richard Nixon. The rest, as they say, is history.

In fairness, Nixon did go on to form the Environmental Protection Agency. He sought to nationalize the welfare system and to expand public housing. On the world scene, he recognized Communist China and, with Henry Kissinger as his agent, practiced balance-of-power diplomacy.

Which brings us back to our present missed opportunities. One does not need a briefing from Dr. Kissinger to know that the next American president has a chance of ending the cold war with the Soviet Union.

Writing in the current issue of Foreign Policy magazine, Richard H. Ullman, a Princeton-based Soviet scholar, notes that the United States has a strong interest in helping Mikhail Gorbachev achieve his objective of restructuring Soviet society. "Success in foreign policy will strengthen his hand for the huge task of (reform)," Ullman declares.

Even though that window of hope is the most profound foreign policy issue on the national agenda, it is receiving scant attention in the campaign. Blame the system - including, if you will, the media. Yet bear in mind that we are all the losers for it.