As election day nears and Barry Goldwater still has not found an issue to make it a contest, a pervasive dullness falls over the speeches, airplane tours, and controversies that usually bring excitement to the Presidential race.

Issues that promised in June to provide extraordinary debate have failed to solidify, partly because Goldwater has never come close enough to Johnson in the polls to provide the President with the incentive for answering his charges.

Even when Johnson condescends to an indirect retort, his strictures against "the voices of extremism" raise no enthusiasm. The lack of response does not stem from disagreement with Johnson, but rather from the fact that most Americans are so overwhelmingly behind him that his philosophical differences with Goldwater seem little more than irrelevant abstractions.

The people seem to have made up their minds on what they considered the practical differences between the nominees before the campaign began. They labeled Johnson "immoral but safe" and Goldwater "moral but dangerous." As one woman in Ohio said: "They have given me a choice between a crook and a kook. I guess I'll vote for the crook." This common judgment, while perhaps clumsy and distorted, did not change much despite the tactics used by both candidates to improve their images. Now as the end approaches it seems certain that not enough people will change their minds to affect the outcome.

But the almost irreversible lead for Johnson--which makes the Presidential contest dull--has turned originally marginal questions into the exciting issues of the campaign, Of these issues the chief fear in Cambridge--one suspects this is also true in other intellectual communities--has turned out, ironically, to be the fear of total victory.

Why not total victory? Well it wouldn't be so bad, liberals say, if we could guarantee that Goldwater and his cohorts would be knocked out of politics forever. But the chance is greater, they reason, that Johnson will whip his opponent just badly enough to defeat all the moderate Republicans who are running for election this year. Senators Fong, Keating, Bell, and Scott are in danger of being swept under along with a nominee who does not represent their views.

If Johnson's victory causes the defeat of moderate Republicans in the North, it will probably not prevent the election in the South of Goldwater Republicans and Dixiecrats, who would give Goldwater a more prominent position than ever in the party's councils.

The Republican representation in Congress would be smaller, but it would also tend more to homogeneous Goldwater Republicanism. The obliteration of many Congressional moderates in the party would also leave Goldwater forces as the only visible leadership alternative, should a catastrophe or scandal that decisively discredited the Democrats occur.

The Congressional strengthening of the Senator's position would have one supremely important mechanical effect. It would consolidate his hold on party machinery in the Nation's Capital. The Arizonan's lieutenants were ruthless in seizing control of that machinery; they may be just as tough in holding onto it. They might well be able to re-nominate the titular head of the G.O.P. in 1968 come what may.

This grip on the G.O.P. apparatus would mean that the event which could unseat Johnson need not take place in the next four years. Even if no catastrophe occurs, Johnson's ability to hold supporters as different as southern conservatives and northern Negro leaders might easily collapse over an eight-year period. If racial tensions increase greatly, the artfice of a President capable of appealing to both groups might become too clear. This does not mean to imply that the elasticity Johnson has shown in seeking support is a bad thing: on the contrary, it is necessary to the consensual charade that many of our most successful Presidents have needed to play.

But consensus does require that the President point to some greater good in togetherness than the reward each follower sees as the end of a separate path. A series of racial riots met by tough police suppression in coming years would make it doubtful that the present consensus based on the prospect of a Great Society could endure.

These are considerations that make some centrists and liberals wish to support moderate Republicanism. But is it possible to keep moderate Republicanism as a viable political power under present conditions? It is easy to scoff at the idea that, as result of a single election, one of our national parties may be dying. Yet it will be difficult for the moderate Republicans to run again with a label which, if Goldwater forces do continue to speak for the G.O.P., will associate them with a philosophy unpalatable to their liberal constituents.

Another great obstacle to their survival is Lyndon Johnson himself, who seems by a process of rapid political mutation to have become more fit than they to occupy their evolutionary niche. It is likely that many businessmen prefer Johnson to Rockefeller. It is not impossible that quite a few industrialists secretly prefer him to Scranton.

What, then, if Goldwater's stratagems to hold party machinery succeed yet nothing appears that would make it possible for him to topple the Democratic consensus? The country would be left for a while with the kind of one-party predominance that has visited the United States from time to time: government which has the deceptive appearance of the "factionless" dream which some of the Founding Fathers entertained.

This would mean that the great power struggle after 1972, if Johnson neither dies nor is assassinated, would be to succeed him from within the party, not to oppose him from without. This is the privilege for which Humphrey and Kennedy are now contending.

Would one-party politics, if it came, be just a phase in the cyclical fortunes of American parties, or would it signify a step toward the increasing number of essentially one-party systems which are emerging in both democratic and totalitarian countries everywhere?

The answer is not foreordained: it must depend partly on Johnson's skill in maintaining the consensus; partly on the course of racial and foreign crises; and partly on whether groups to the right and left of Democratic center succeed in formulating realistic alternatives to centrist policies. So far, the capacity to think out such policies is something that neither side has shown any signs of developing.