IN THESE turbulent times, when one yearns for a sense of permanence in politics and government, there is always Evans and Novak.

Their breathless prose sometimes leaves the reader out of breath, but Evans and Novak are an island of constancy in a frivolous world. I thought they had more authority as commentators when they used to run little thumbnail photos. Evans and Novak looked so somber and certain, it was reassuring on days when their words sounded frantic. I miss the pictures.

Still, they are extraordinary reporters and usually the first to reveal the latest wrinkle in the right-center conventional wisdom of political Washington, which is why they are so influential. Other columnists follow and feed on the grain that Evans and Novak harvested.

Since Joseph Alsop retired, Evans and Novak have had the Russian menace all to themselves, keeping us posted on the latest Soviet weaponry. I miss Alsop too. None of today's columnists keep up with the "captured enemy documents" which Alsop used to analyze so thoroughly or flog the "bottom-dwelling slugs" whom Alsop saw in our midst.

Life goes on and Evans and Novak are resilient, even rock-like, in the changing scene. They discover new sources who, like the old sources, are tough, canny, pragmatic, astute, influential. One reads less about the tax philosophy of Wilbur Mills, the ex-influential chairman of Ways and Means, but we hear a lot about the rising star of Jack Kemp, the young congressman with the hair.

But the presidency is the main meat: the secret White House memos, the brilliant breakfast briefings, the key phone calls and ominous marginal notes.

Small things seem desperately important in that magical world and, somehow, these two reporters are able to uncover the inner anxieties of the president's court. For instance:

"President Carter's inner circle hopes proliferating talk about him not seeking a second term in 1980 will be quashed by the long-delayed announcement of a citizens' committee for his reelection."

The columnists have exposed the well-concealed dangers in the president's blatant political manipulation of foreign policy:

"Deepening dependence by Jimmy Carter on his role as peace president to give him a second term in the White House is now causing well-concealed anxiety among some of his top-level foreign policy experts that he may unwittingly make himself a hostage in Moscow hands.

And, to test the political climate, Evans and Novak regularly consult the grass roots, where they find more gloom:

"LaGRANGE HIGHLANDS, III. - In this comfortably prosperous white middle-class suburb just west of Chicago, dissatisfaction with the economic policy of President Carter runs so deep it could devastate him in 1980 .. . .

"That is the only conclusion that can be drawn from eight hours of interviewing registered voters here with the Oliver Quayles polling organization. These predominantly conservative Republican voters, while enthusiastically endorsing Mr. Carter's China initiatives, made clear that they are much more concerned about dollars-and-cents issues - particularly inflation."

Ravaging inflation, appeasing the Reds, the possibility of a one-term president. Jimmy Carter's predicament is mercilessly laid bare.

I have taken a small, unforgivable liberty in quoting from Evans and Novak, for which I instantly apologize. These Evans and Novak comments were written in 1971 about President Nixon. I merely substituted Carter's name for Nixon's and the 1980 election for 1972. I discovered that these old reports still sound quite authoritative eight years later.

My thoughts keep returning perversely to the summer of '71 - when Nixon was in deep trouble - perhaps because none of the political pundits seem to remember that season or what they wrote. It's unfair of me to single out Evans and Novak because there was a general chorus of gloomy prophecy.

Many of the flaws and fumbles which political columnists now perceive in President Carter are the same ones they saw in Nixon when he was in political "deterioration," as they would call it. Joseph Kraft, for instance, saw Nixon's vulnerability in '71 stemming from "a pattern of no follow-up." "A lot of little things - matters of timing and style and presentation - cause the public to make a discount for even his most genuine accomplishments," Kraft wrote then.

Nixon was not as low in the Gallup Poll as Carter is now. On the other hand, Nixon was losing "trial heats" in the public opinion polls against that celebrated front-runner, Sen. Edmund Muskie. Carter has not been losing "trial heats" to Republican opponents.

Evans and Novak on Carter, if anything, sound slightly more sympathetic than Evans and Novak on Nixon, but the same apocalyptic themes and phrases reoccur. "The emperor with no clothes . . . despair over the decline of American power . . . the last straw alienating the liberal community . . . rapid political deterioration . . . political fumbling of a kind chronic in his White House."

With the luxury of hindsight, we know how wrong the political wisdom was on Nixon in '71. That season, he imposed wage-price controls and pumped up the economy to a superheated level. Later he signed an arms treaty with the Russians and cooked up a phony peace settlement in Vietnam. And Nixon won reelection by an historic landslide in 1972. As a winner in '72, Nixon was celebrated in the press as an effective politician, a good manager of government. Later, when the truth of Watergate unraveled, the conventional wisdom changed again. Joseph Kraft and Evans and Novak distinguished themselves during the Watergate episode, perceiving its real dimensions and pursuing the unanswered questions vigorously, when most other columnists didn't get it.

Of course, if political Washington was wrong about Nixon, that doesn't mean it is necessarily wrong about Carter, does it? I am reminded of a wonderful old country expression from Kentucky politics: "Even a blind hog rooting in the woods will find an acorn now and then."

A slanderous metaphor, which probably calls for another apology. Eugene McCarthy, the poet, has likened political pundits to blackbirds sitting on a wire, a more cheerful comparison, if you like birds. When one flies, they all fly.

Between blackbirds and blind hogs, I still read the political columns regularly and enjoy them, even though I regard the heavy judgments as perishable insider gossip. The trivia of Washington politics gets less interesting as politics generally becomes more trivial, spiritless, timid, cloaked in unconvincing gimmicks and machine-tooled rhetoric. Still, I like Evans and Novak.

I think this is partly nostalgia. Evans and Novak still believe in the efficacy of electoral politics and, implicitly, in the magic powers of the presidency.To me, they sound like an old-fashioned fundamentalist preacher, defending an embattled faith. It is reassuring to read these old sermons, occasionally amusing in their hyperbole, even if one has lost the fiath.

The dying faith is really quite primitive in its logic. Columnists examine the behavior of presidents, much the way ancient shamans would scrutinize tribal kings. In the same way, the president embodies the government and all forces for good or ill. If the crops fail, the king must die. If the people feel abundant in their lives, then he must be a helluva king and will surely win the New Hampshire primary. If one reads Frazier's classic anthropology, "The Golden Bough," and then reads Evans and Novak, it is startling how little the mystery of the leader has changed in 2,000 years.

Is it possible, I wonder, to accept a more complicated logic of politics and leadership without losing faith in democracy. I think so. At least I hope so.

Political Washington still insists upon the simple-minded creed - that presidents make good things happen and, if good things do not happen, then the president is examined for flaws. His style, his speeches, his political wink, his courtiers, his haircut. Sure enough, flaws are found to explain the bad times.

But we ought to know by now that presidents are always less than they seem. The skillful ones play with mirrors, make themselves seem larger than life. The maladroit, like Carter and Nixon, magnify their own weaknesses and deepen the illusion of personal failure.

Meanwhile, all of them, skillful or clumsy, confront similar problems and counterforces. They disappoint old friends and tread the same fine lines. They plead for cooperation with the same rival centers of power - Congress, Wall Street, the Pentagon, George Meany, the oil industry, farmers, and so on. A great deal of what happens in America, much of what happens to a president, does not really depend upon his style, rhetoric and timing.

I hope Carter is able to run as the "peace president" next year. After all, the "peace candidate" won in 1964, 1968, 1972 and 1976. Carter's personal energy crisis and his hapless battle with inflation could, of course, still defeat him. Either way, Evans and Novak will explain it for me.