Beth Arnoot, a mother of three, had come from her McLean home yesterday to stand in the rain in front of the White House with a simple sign. Nearby were Dana Lane, of Denver, whose 23-year-old Army son is stationed in Saudi Arabia, and Mike Lynn, 22, an express mail employee from Alexandria.

None had participated in a protest, but they had come to deliver a simple message, ignored ultimately by President Bush: No war.

"The only organization I've been involved in is the PTA, but this was something I felt I must do," said Lane, 40, who has been fasting for two days. "I'm scared."

Similar sentiments have reverberated across the nation this week as tens of thousands of Americans demonstrated against the likelihood of war in numbers far greater than organizers had anticipated.

In Los Angeles yesterday, about 500 demonstrators, many dressed in T-shirts with slogans such as "How Many Deaths Per Gallon?" scuffled with club-wielding marshals. They succeeded in closing a busy federal building for three hours at midday; 158 were arrested.

Similar demonstrations erupted throughout the western states as well as in Boston and Chicago, where demonstrators also tried to block the entrances to federal buildings.

Although demonstrations appeared smaller yesterday and fewer in number than earlier in the week, organizers described the lull as temporary, and said they will gear up again significantly after the start of hostilities. Hundreds of protesters are scheduled to come here from around the country this Saturday and next Saturday to march in front of the White House.

At the White House, where thousands of protesters gathered for candlelight vigils on Monday and Tuesday nights, about three dozen demonstrators stood quietly in the rain yesterday, holding up signs or pacing the sidewalk during the noon hour. Arnoot, like others, said she came because she did not know what else to do.

"I thought if {Bush} could see people saying no, it might make him stop," said Arnoot.

The presence of first-time demonstrators such as Arnoot at the White House -- middle class and middle-aged -- has surprised even longtime activists accustomed to the vagaries and difficulties of organized protest. Although the protests, prayer vigils and teach-ins have resounded with many of the same themes and songs of the Vietnam War demonstrations, organizers stress that there are major differences between protests then and now.

First, these demonstrations began before war broke out, not after. Unlike the primarily white college students and professors who made up the core of the Vietnam War protests, today's demonstrators seem to come in every age and class.

"In the Vietnam War protests, it was more of a white protest," said Barbara Davidson, president of a union local at the U.S. Department of Housing and Urban Development. The local passed a resolution condemning the presence of American troops in the Persian Gulf, and is a co-sponsor of this Saturday's march. "This time it is much more multinational."

The major churches and labor unions, largely absent in the early days of the Vietnam protests, have taken a major lead in opposing this war. Most major Christian denominations oppose a war in the gulf now, and prayer vigils have been conducted throughout the District and the country this week.

On Monday night, more than 5,000 people jammed Washington Cathedral for a prayer vigil, the largest assembly ever there. The participants then marched three miles in an hour-long candlelight procession to the White House. Among 1,500 protesters who stood in front of the White House on Saturday, nearly half were Unitarian Universalists.

Nine major unions, including the United Auto Workers and the International Longshoremen's , wrote an open letter to President Bush, opposing a U.S. offensive, which was published as an advertisement this week in The Washington Post.

"In the anti-war movement of the '60s, the leadership at the top of the unions was very conservative," said Davidson, who has successfully lobbied several union locals in this region to endorse an anti-war resolution. "This is rolling through the union leadership very quickly."

Elsewhere around the country yesterday, several hundred protesters tried to block the entrance to the John F. Kennedy Federal Building in Boston. Chanting "No blood for oil," some poured red dye on nearby snowbanks to symbolize the blood of war casualties. Later in the morning, about 30 protesters were arrested when they blocked the entrance to the automobile tunnel under Boston Harbor.

The successful effort to close the Los Angeles federal building drew many high school students, veteran anti-war activists and even the city attorney of Santa Monica, Calif. Actor David Clennon, who plays the sinister advertising agency head on the television show "thirtysomething," served as a marshal for the protest, and addressed the crowd.

Several high school students were arrested after a sidewalk skit portraying American businessmen picking dollars off the bodies of American youth. Several older demonstrators, including some in their seventies, also were arrested.

In Olympia, Wash., state Rep. Dick Nelson (D-Seattle) said he expected approval soon of the nation's first state legislative resolution opposing military action in the Persian Gulf. Nelson said legislators were galvanized by several hundred student demonstrators who took over their chamber Tuesday. Ten remaining demonstrators were removed from the chamber Wednesday morning.

Anti-war protesters have succeeded in temporarily blocking traffic on Interstate 5, the main route through Seattle, four times this week.

San Francisco anti-war activists, so far the best organized in the West, said they were putting most of their efforts into a planned Saturday march expected to draw 20,000 people.

Another San Francisco protest is planned for Jan. 26, with support from "everyone from Republicans to the left of the left," said Hilary Diamond, a staff member of the organizing coalition. "We want an event where grandmothers can come and feel comfortable."

A small group of demonstrators camping in front of the state capital in Sacramento, Calif., planned a march to the federal building there.

In Montezuma, Ariz., 49 students representing 23 nationalities at the Armand Hammer United World College began a five-day hunger strike to protest war in the Middle East.