When Ronald Reagan was governor of California, it took a quiet conspiracy of his staff and a confrontation with Reagan to prompt him to oust key aides accused of involvement in a homosexual scandal.

When Reagan was running for president in 1980, it took a "me-or-him" ultimatum from campaign manager John Sears to force the candidate to choose between Sears, whom he fired, and Edwin Meese III, who stayed to become White House counselor.

And when top members of Reagan's presidential staff, including chief of staff James A. Baker III, wanted him to cut his political losses by easing out Secretary of Labor Raymond J. Donovan, the president decided that Donovan was the victim of a vendetta and kept him in the Cabinet.

All of these examples were cited by administration officials last week as they tried to explain why life in the White House has become so difficult after nearly two years of the Reagan administration.

On the surface, what seems to be occurring is the fine old Washington sport of inside power politics.

Baker is the target of right-wingers who see him as some sort of closet liberal who wants to reconvert the president to the New Deal. Meese, a pragmatic conservative who has become an unlikely hero for the right wing, is a victim of constant sniping from those who think he wants to be more than a counselor.

Deputy chief of staff Michael K. Deaver, "the keeper of the body" and the aide most sensitive to Reagan's moods and physical condition, is assailed by many for becoming overly protective of the president. National security adviser William P. Clark, long trusted by Reagan, is a shadowy figure to some domestic issue specialists, who worry that Clark will invade their turf.

What is really happening is less a power struggle than an exercise in frustration. After two years of collective leadership, strains are showing, and authority is so fragmented that nearly everyone in the White House is complaining about the difficulty of making even the simplest decisions. The troika of Baker, Deaver and Meese has become, with the addition of Clark, a quadruped, which might be defined as a kind of great shambling beast going in all directions at once.

Frustration has descended to a level of trivia that brings no credit to Baker and Meese, good men who in rational moments realize that they need each other. The two wound up in a shouting match the other day after Meese aides staged a presentation for the president that contended Baker's staff had given less money than Meese's staff to the federal campaign for United Way.

Grown men should spend their time in better ways. Missing at the White House these days is the presence of a decisive leader who will resolve the staff conflicts and get everyone pulling in the same direction.

Some say that leader should be Baker, a competitive but cautious man slow to exercise the theoretical weight of his position. One Baker intimate says he could use "a little bit of Bob Haldeman" in his makeup. Others contend that Deaver, who prevailed in opposing a visit by Reagan to the Vietnam Veterans Memorial, should be less protective. Some want Meese to spend more time at the White House.

The real missing ingredient is Reagan, described by one aide as being "hopelessly above the battle" and by a longtime Reagan insider as becoming "out of touch with the struggles in his own administration."

This insider adds: "Ronald Reagan is a passive man who needs events and bold people to force him to act. The events haven't happened, and the cautious people on his staff are canceling out each other. In a corporate style of government, you really need a chairman of the board."

Reaganism of the Week: Asked early in the week whether he would visit the Vietnam memorial, the president replied: "I can't tell until somebody tells me. I never know where I'm going."

One person who knew where he wasn't going was Robert P. Nimmo, the ousted, perquisite-loving VA administrator who critics say spent more time on the golf course than tending to the needs of Vietnam vets. His last act of contempt was his decision not to go to the Vietnam memorial.

Curious Claim of the Month: John T. (Terry) Dolan, chairman of the National Conservative Political Action Committee, listing Republican Chic Hecht in Nevada as one of NCPAC's "wins" in the midterm election. In fact, one reason for Hecht's success was that he quickly repudiated NCPAC and told the organization to stay out of Nevada.

Non-Question of the Year, presidential press conference division: "Mr. President, in two weeks the United States will celebrate Thanksgiving," said Lee Roderick of Scripps League Newspapers. "Given the passing of Brezhnev, inevitably there are comparisons between the two systems. Could you take just a minute to tell Americans why at this time they especially should be thankful for their blessings and give a comparison of the two systems?"

And maybe, while you're at it, Mr. President, compare the ways in which Halloween is celebrated in the two countries.