He stands there, larger than life, calm, contented, beaming: the glistening photograph of President Reagan greets every visitor to the presidential inaugural headquarters in Anacostia. But several feet away is the icon that really matters now. "65 days left to the Inaugural" it read once upon a time, a promise reaching far into the future.

Not anymore.

All around Washington, teeth are gritting, hands are developing little tremors, lists of thing that "MUST BE DONE" are growing more intimidating. There are four days until the quadrennial event that, for some, has become more than an overcrowded agglomeration of parties and ceremonies.

For some, at least for several weeks, it has been the engine that drives their lives. The Chairman

Ron Walker is smoking again.

"I don't usually smoke," says Walker, chairman of the Committee for the 50th American Presidential Inaugural, as he stubs out a cigarette he seems to have consumed in one long, furious drag. "But as soon as I got the job, I bought a carton of cigarettes."

Walker, who managed the Republican National Convention last summer, said he refused to run the inaugural when White House deputy chief of staff Michael Deaver first approached him. But then he began to think. And then he said yes.

"I work very hard," says Walker with no hint that the understatement is deliberate. He has just explained that he is again putting in 18-hour days, getting up at 4:30 a.m., reaching his office at the executive headhunting firm Korn/Ferry International by 6:30 for a few hours there before settling in at the committee for another 12 hours, and skipping lunch -- not eating at his desk, just not eating. "After Dallas, it took me a long time to come down from the ceiling. I didn't sleep for a week. I just lay there and I refought all the wars in my head."

And now there will be new wars to refight.

"It was another challenge," he says, a delicate description of a job that involves running 250 paid staffers and 6,000 volunteers, managing a budget of $12- to $13 million and navigating the dangerous waters surrounding a Washington tradition where the potential for financial disaster and symbolic catastrophe lurks behind every decision.

Take the recent controversy over an ad placed by a committee consultant asking for "clean-cut" actors to perform in the galas this weekend for free.

"You think you've got everything wired for sound, right?" says Walker, grimacing, and launching into a defense: more union people in this inaugural than ever before, ad not cleared with committee, ad "insensitive."

It's this kind of crisis -- a crisis of interpretation -- that characterized much of the reaction to the 1981 inaugural and that Walker wants to avoid, although he phrases that desire carefully.

"I'm very cautious," he says, when asked about criticism of the 1981 inaugural.

"You do the best you can when you do it. That's exactly what Bob Gray and Charlie Wick did last time. They had come to town new. They had come off of a tough campaign, a gleeful win, euphoria surrounding, and they brought their personalities and that's exactly what it was. There were a lot of things that were not done well four years ago, but hindsight is the greatest rule of judgment there is. Be there on the firing line when it's going down."

If the rest of the world is moving at 45, Walker passed 78 a good nine weeks ago. He seems never to blink -- it's too time consuming. His office is packed with paraphernalia both specifically and generically patriotic, from inaugural cocktail napkins to a red, white and blue ice chest topped with a gold eagle. Two identical leather briefcases -- one for the inaugural, one for Korn/Ferry -- wait by his desk for the quick change from one life to another.

"We got to take four days off for Christmas," Walker says. "That was real neat."

Walker came to all of this via the White House advance office and the National Park Service, where he was director. His wife Anne quit one job and volunteered for him in Dallas before joining the Commerce Department in the public affairs office; one of his three daughters painted signs for the convention. Now he tries to see them as much as he can -- which is not much.

He speaks in mottoes and his walls are plastered with them: "No job is too difficult for a man with good assistants"; "Get people who are smarter than you are and stand on their shoulders"; "It's for the president! It's for the 50th inaugural! It can be done!"

"We felt that if people got the invitation, go out and buy a beautiful gown, the husband pulls out the black tie, gets the patent leather shoes, cummerbund, and comes to the nation's capital, we want it to be a new experience, a quality experience."

Recently, the rumor circulated that Walker might replace Deaver in the White House. He says it is not true.

"No, ma'am," he says. "I'm going right back to being managing director of Korn/Ferry International. We have had some discussions, but I feel at this point in my life, it's best that I return."

And not take on another convention or inaugural.

"Why?" he asks. "I ran one of the better conventions, I'm told, and I hope this will be as good." The Historian

When Ulysses S. Grant was inaugurated as president for the second time, the food froze. It was sleeting, the temperature was below zero, musical instruments didn't work, cadets fainted, and at the ball the canaries, which had been hung in cages from the ceiling and whose song was expected to charm the guests as the evening passed, all froze to death.

"It is a lot of trivia, if you start looking at it in this light," the historian and archivist for the 50th inaugural, Jerry Wallace, says somewhat apologetically. Wallace, who works at the National Archives between inaugurals, has three functions at the committee: to provide the planners with useful documents from past inaugurals, to collect the masses of paper the committee extrudes during its three-month existence, and to tell people about things like those 19th-century canaries.

But trivia, as Wallace knows, is all in how you look at it.

"Sometimes you can see some very strong political elements," he says.

Take FDR's inaugural in 1945, when he held the ceremony at the White House instead of the Capitol.

"There are a lot of excuses for why he did it: he wanted to save money, he wanted the security, his health." But Wallace thinks it was something else. Roosevelt's relations with Congress were a little rocky and what better snub than to relocate his inaugural?

It's one of Wallace's favorite historical theories, and his face lights up with delight as he tells it. The inaugural stint, Wallace's third, is more than a temporary job for him. He loves the stuff, loves the facts and the theories and the idea of the inaugural itself. And, like any history buff, he appreciates the way inaugurals cut time into four-year chunks, establishing neat historical demarcations and throwing progress into perspective.

"Until 1921, unless you were on the platform or right in front, you couldn't hear the inaugural address at all," he says. "Then, in 1921 for Harding, they had loudspeakers for the first time. In 1925, through radio, Coolidge's address went to most of the major cities on the East Coast. In 1929, for Hoover, it was nationwide, and through shortwave, it went to Leningrad, to Tokyo, and even Admiral Byrd, floating on a block of ice, heard that address. In less than a decade -- can you imagine?"

And, of course, inaugurals reflect tellingly on the times.

With the issue of female suffrage confronting the nation in 1917, Wallace says, Wilson's inaugural parade included a prominently featured contingent of women.

"Blacks, of course, appeared for the first time for Lincoln in 1865 as an organized-type unit," he says. "Eisenhower's in '51 -- this followed Little Rock. There was a great deal of emphasis in that on different ethnic groups, different religious groups, coming together in harmony and peace."

And the 1981 inaugural, with its morning coats and white tie and dinners that demanded description that went beyond "opulent," tells a story too.

"Last time, I think the president was interested in trying to boost the spirits of the American people. At first it's hard to understand doing that with money and that kind of thing, but I think it's like the royal wedding in England several years ago. The British do it very well. Britain was in very bad economic shape, and the wedding did boost the spirits.

"It makes sense for the president, because Reagan's an optimist -- to show people the world's going on, and life's going to continue." The Hostess

The work has been with tablecloths and menus, flower arrangements and music, but for Ann Mathias, who is arranging the lunch Congress gives the president following the swearing-in ceremony, even the background music must be more than just pleasant.

"It's the 50th inaugural, and it's a good time to think 'Who are we? What are we about?' " says Mathias, whose husband, Sen. Charles McC. Mathias (R-Md.) is chairman of the Joint Congressional Committee on Inaugural Ceremonies. So the music, played on original 18th- and 19th-century instruments, will date from the United States' early years; the guests will include six private citizens representing the nation's population and the food, while certainly not modest, will avoid the excessively esoteric.

The lunch, which begins with sole mousse, moves on to medallions of veal with wild rice and chestnuts and ends with praline souffle' with raspberry sauce, will be prepared, after much deliberation and sampling by Mathias, by Glorious Food.

"I set up a tasting committee," she explains, "and one of the things I explained to them was that I didn't want food that was so effete that nobody in the United States could relate to it. I wanted a meal that fell within a category which might be obtained on a feast day for the average family."

All of which relates to what Ann Mathias feels the inaugural means.

"I think Uncle Sam is a pretty terrific guy," she says, "and I thought this was a great opportunity to show my love for Uncle Sam. He deserves to be patted on the back, and told despite his blemishes, of which we're all aware, that he's a pretty good fellow and we're lucky to have him."

Arranging for the pat on the back has kept her working long hours since mid-September, suggesting music for the ceremony (Aaron Copland's adaptation of the Shaker song "Simple Gifts"), quotes for the program (Jefferson, Madison, the Constitution and Declaration of Independence) and flowers for the lunch that will enhance the colors in the Capitol's Statuary Hall.

She thought the hall would be more hospitable if a painting, preferably one by an American Luminist, hung behind the head table. The National Gallery supplied one: "Autumn on the Hudson River" by Jasper Francis Cropsey.

She wanted something to draw the guests' eyes away from all the bronze and stone knees of the statues that face anyone sitting in the hall. Hanging flower arrangements will help.

As she walks through the hall, she greets the man doing a last-minute paint job, points out the corn motif above a fireplace she chose to decorate the lunch program, rubs her hand across the mottled marble columns she loves so much, sliding her palm across the cool marble like a mother caressing a child.

"In a funny way, this has really been fulfilling for me," she says. "It has enabled me to focus on what it is I respect and love about this country. That sounds high blown and high floating, but it's true.

"I was honestly and truly thinking about the basic simplicity which is at the root of what this country means. I feel that when I go to the Midwest -- the people are real, they're humble in the right sense of the word. I see it in the Maine fishermen whom I know intimately. We are a real people.

"The lyrics to the song 'Simple Gifts': ' 'Tis the gift to be simple/ 'Tis the gift to be free/ 'Tis the gift to come round where you ought to be . . .' It absolutely undoes me."