A WAVE APPROACHING shore builds slowly, the glassy, sloped back hiding the roiling currents underneath. The crest grows more and more quickly; the higher it reaches, the more precarious its base becomes. And every time, the wave topples, sometimes earlier and sometimes later, its peak crashing into its middle and exploding in foam.

A few years ago, everyone had his personal vision of the end-time, inspired by any one of a thousand doomsaying paperbacks. In some, people stood close together, two to each square foot of soil. Others gave dreams of the winter without oil, or the year that the Third World collectively decided it had suffered long enough at our expense and sent vanguard elements to wreak havoc. Many feared nothing more complicated than nuclear holocaust; and a few still thought that, after all, it might be the Communists. If the peddlers of survival gear are to be believed, people have of late begun to act on their fears, caching enormous stores of dehydrated food and Geiger counters and, especially, firearms.

There's never been too much point to the apocalyptic faith--believe in it, and all you can do is wait for it. But last Tuesday night leaves us little choice; perhaps it is only temporary, but perhaps, too, some future Gibbon will begin his introduction like this: "November 4, 1980, Americans went to the polls to choose their 40th president..."

Ronald Reagan's election is not the biggest source of despair--rather it is the confluence of the size of his victory, the triumph of other conservatives (especially a half-dozen Bible-believing absolutist senators), and the apparently terminal case of tax fever that felled even the residents of Massachusetts. And the results of last week's elections are not, by themselves, the heralds of Armageddon. Instead, they are proofs--compass checks--of trends a few years older. They demonstrate that the car has gone over the top of the roller coaster, that the nation is shrieking and waving its hands in the air, and that gravity has taken over.

JIMMY CARTER Tuesday became the first elected president defeated in half a century, the first incumbent Democrat cast out in more than a hundred years. He won but six states, and they were little ones. Working class Americans deserted him, Catholics, Jews and liberals too. And then there was George McGovern, a Senator for two decades and once a presidential candidate who stood firmly opposed to the slaughter of Vietnam, who put forward a much-ridiculed plan to guarantee a small income for all Americans. McGovern was beaten badly by Jim Abdnor, for whom "slaughter" means instead federally funded abortion, who promised to cut taxes instead of supporting those "too lazy to work." With Carter and McGovern went Frank Church, John Culver '54, and Birch Bayh. Here in Massachusetts, the people overwhelmingly approved a huge reduction in local taxes, despite the warnings of city and town officials that the cuts would cripple local schools, reduce the number of cops on the beat, and make driftwood of the state's poor who depend most heavily on public help.

Somewhere here there is a message--the nation's syndicated psychoanalysts quickly diagnosed a shift to the Right. Cogent, even obvious, but incomplete. The 1980 election either represents widespread dissatisfaction with Jimmy Carter (the majority op-ed view) or a near-total realignment of American politics, a conclusion more dour but also more plausible.

Until 1932, peacetime federal government meant very little. Americans believed in letting money do as it pleased, with unfortunate results for many people from the start and for almost everybody in the decade of America's greatest economic collapse. For the next 40 years bureaus sprang full-blown from the heads of Democrats, as our nation decided that only collectively could it solve the enormous problems of an imperfect society. But that consensus began to falter in the late 1960s, when Americans chose Richard Nixon, and in 1972, when they chose him again, emphatically. Watergate intervened, throwing an election to the Democrats. But then came Proposition 13, and inevitably behind it Ronald Reagan, the Kemp-Roth tax cut, an end to the Environmental Protection Agency, the death of the Equal Rights Amendment, a one-sided partnership between business and government. In short, the restoration of the same American dream that once made tranquil the sleep of Calvin Coolidge but haunted Herbert Hoover.

This is a reversal we can't afford. If America chose in the late 1800s to ignore populism and place its faith in an expanding economy, to ignore the plagues of race and sex discrimination, and treat the rest of the planet as if it were a warehouse to be looted, it meant trouble for a few generations of Americans. But now we are trying the same thing in a day when the rest of the world demands and deserves a share of the world's wealth. In an age when the fact of scarcity--the idea Reagan and his men hate most, that they try to hex away with statistics about oil reserves and mineral supplies--makes even the myth of an ever-expanding industrial economy seem ludicrous.

The foreign policy technicians of the Right spent much of the campaign assailing the "new world order" theorists they found lurking in the State Department, those men who have seen that America and Western Europe can no longer gather in all the world's wealth, leaving whole continents ravaged. Abdnor, Dan Quayle, Steve Symms--these men subscribe to the Reagan "placed here between two great oceans" theory of the American mission. To the scientists who predict that pollution, and overproduction, and depletion spell disaster, the Republicans shout Pollution is From Trees. There are New Sources. We Can Get America Moving Again. Just step on the clutch and put it in reverse.

MORE SANGUINE observers are already calling 1980 an aberration, predicting a return to the fairly clear course of mid-twentieth century liberalism, perhaps as early as 1982, or when Ted Kennedy wins the White House in 1984. But the trend of the last decade proves them wrong--except for the perturbations caused by presidential scandal, America has been moving to the Right for years. Even if the Democrats do regain some measure of national power, they will still have to content themselves with defending the current size of government, for the prevailing view in America will not allow new regulation or new growth in bureaucracy.

Democrats in office will conform increasingly to the new orthodoxy, and change will roll back, a Sisyphean boulder down the slope of the latter curve. And even if the pause lasts only a decade, it will be too long. The great experiment of the last century, conducted primarily in the United States, has been to see if we could keep the wave from crashing, somehow moderate its peak or build up its base so that it never hits shore. Americans, in 1980, have given up on that experiment, which demands quick analysis and dramatic, constant change, with hardly a look back. It is unlikely that we will renew the quest before scarcity hits America as more than just lines on charts.

Surely many expect a concerned and competent crowd of young politicians to come to the rescue; the current cycle of conservatism, though, makes such relief unlikely. To enter politics has traditionally required either a strong belief in meliorism or a strong belief in graft. But in a state where the taxpayers have finally refused--and loudly--to provide new support, there is no reason to believe government will be able to do much to solve the existing problems. The rising rhetoric of new, improved and inexpensive liberalism is illusory; at best, a young liberal will spend his days in office battling the erosion of social programs and government regulation, fighting a desperate rear guard action for the ragtag Great Society. A Cambridge city councilor next year will not be able to improve police protection, or deal with youth problems, or even see that the potholes in Mass Ave are fixed. He will spend his term instead trying to find the least damaging cuts in services--which is more important, teen centers or Meals on Wheels? Do we put 35 kids in each class or abolish the rent control board? Increasingly, conventional politics will become an irrelevant profession, for without voters agreeing to increases in the current levels of taxation, little new can be done. And so young men and women not yet wedded to the profession will gradually drift out of the political arena. That they will take with them the corrupt, unable to feed off the bones the tax-slashers leave behind them, is small solace.

And even should a thousand Quixotes astride Democratic donkeys sally forth to take up the gauntlet, they stand no chance. The American majority will sleep blissfully for the next 10 or 15 years--they years when our slide gains invisible but irresistible momentum--dreaming only of increased discretionary income. Reagan and his ilk, assuming they can avoid war and keep the Pentagon to five sides, will be able to solve inflation in the short run, and that's all that really troubles Americans. Reduced government spending, coupled with a traditional industrial base growing to meet the demands of Betamax-hungry consumers, will make the economy seem healthy compared to the current transitional chaos. And the political rewards of such success will go, naturally, to those who have created it, the alchemists of the Republican right.

THWARTED IN THE usual provinces of politics--elected office and organizations seeking to influence those who hold such office--the next generation of the Left will have to find some other outlet for its activism. They can't be lobbyists, for it does no good to lobby someone who keeps quoting from the Bible, someone who has no money to build a decent prison, someone who points to unreclaimed strip mines and calls them "unavoidable consequences of progress." They'll have to follow an impulse that has always existed within the American Left--direct community efforts to create non-governmental institutions. There will be a spate of new schools and neighborhood patrols, and the libertarian movement, on the other side, will continue to pick up steam, as people realize that when government won't solve problems for everybody at once, small-scale community solutions are the only possibility.

Even organizing a neighborhood, though, requires some interest on the part of the neighbors, an interest the opiate of short-term economic gain will dull. And anyway, the organizers will recognize soon enough that improving one corner of Cambridge while the country, and with it the world, heads toward cataclysm is like serving drinks aboard a 747 as it nosedives into the Pacific. When that realization dawns, survivalists won't be the only ones buying guns. Americans believe blissfully that political violence is impossible here, overlooking the wave of bombings that rocked this country in the late 1960s. Backed to the wall by a rock-ribbed government looking to exorcise the Bolsheviki, the trouble will begin with bombs and escalate till it reaches Jamaican proportions. Where it might as well end, for when America bleeds, the left will not fare well. Who, after all, stands by the right to bear arms, besides the Right who bear arms?

SOME WOULD CALL even this an optimistic scenario; surely, they say, we will all be blown to pieces in some Armageddon choreographed from reinforced concrete bunkers in the Urals and the Rockies, and perhaps they are right. Others will snicker and say that life goes on; for a while it will, very much as normal. Sooner rather than later, though, the danger will become apparent, a danger so contrary it manifests itself in believable ways only when it becomes too powerful to be checked. The lights will not turn off all at once some morning, but the newspapers will hint at it, and soon there'll be a crisis that they'll have to put on television.

Scientists traditionally conclude with suggestions for further research, and doomsayers with a list of ways to avoid the bad time ("The aerosol can must be banned, the United Nations must produce eight billion condoms"). Perhaps there is some way out--solar energy, if it is developed quickly despite the neglect of our government, might buy us one more decade to face our troubles. But technological gadgetry is not enough to solve the human failings that have placed us in this predicament; maybe nothing is enough. Maybe there's just personal salvation: in a life spent trying, a life spent setting a non-violent yet non-compliant alternative to the irrational as it builds from every side and all around, a life fighting battles that can't be won. Maybe man had no chance of ever shaping the wave, of preserving its curl, but the delusion that he did brought him closer to it. And had we been skilled enough, it would have been very odd, and very beautiful, to watch the wave roll on without breaking, higher and higher.