Senior Regional Correspondent

If you’re a group of activists trying to sustain a nationwide protest movement in 2011, you’ve got a choice. Either you can look like derelicts, or you can break the law.

But you can’t do both, or you’re bound to lose the popular sympathy and support you desire and need.

The Occupy movement is learning that hard lesson in cities across the nation, where its demonstrators have squatted in public spaces to press to reform America’s grossly inequitable economic power structure.

In New York and other locales, activists failed to protect their image adequately. Their campgrounds were linked to sanitation problems, drug use and other woes. Mayors have ordered police to break up the camps — whose very presence typically violated some municipal ordinance — amid little public outcry.

Happily, however, Washington is emerging as an exception. Protesters and authorities are each doing their part to help the campaign succeed.

Occupy D.C. protesters march in the District’s downtown. They then served pie to everyone at Franklin Square. They put a sign on the food table that read "OccuPIE DC." (Sarah L. Voisin/THE WASHINGTON POST)

Until Saturday, apart from six arrests Nov. 4 and some other scattered incidents, the effort here had been surprisingly free of controversy. The temporary occupation Saturday of the old Franklin School building by Occupy supporters, which led to at least 11 arrests, could be a sign of a more confrontational approach.

If the earlier cooperation can be maintained, however, then the downtown tent villages at Freedom Plaza and McPherson Square could become nuclei for something special: a nonviolent, self-policed movement that increasingly allies with similar-minded groups committed to liberal change.

Earlier last week, there was evidence of a positive trend in Washington in the entirely peaceful, orderly march by Occupy activists to the Key Bridge on Thursday.

Demonstrators marched briskly with a police escort down K Street and through Georgetown. At the Potomac, about 300 protesters respected police guidance and stayed on the sidewalk above the river so as not to block traffic across the bridge.

Number of arrests: zero. Contrast that with the hundreds detained in New York and Chicago the same day, the two-month mark of the Wall Street occupation that sparked the movement.

Another promising feature of Thursday’s march was the large involvement of labor activists, especially from unions representing telephone workers, nurses and teachers. Their presence allayed concerns I expressed in an earlier column, in which I worried that the Occupy movement was too divorced from working-class people who ought to be its natural constituency.

William Steele, 47, vice president of an Annandale local of Communications Workers of America, said of the Occupy campaign, “Ultimately, they have the same desire as we do, which is to fight to preserve the middle class.”

Partly because of the union members’ presence, this group of marchers was more racially diverse, less uniformly young, and, well, just more respectable looking than those at an earlier Occupy rally I attended.

The good order and appearance had a favorable impact on observers along the way.

“It seems fine. They’re civilized about it,” Tamara Edghill, manager of the Godiva chocolate shop on M Street, said as the marchers went by.

Nearby, at the Evolve beauty salon, employee Morena Manjivar agreed: “They need to protest. Somebody needs to listen to us, and this isn’t messy.”

As for the two camps themselves, Washington’s experience has been different partly because the liberal Obama administration and D.C. government sympathize with the cause. They are looking the other way rather than enforcing laws prohibiting long-term encampments in public parks. Why crack down on people with whom you agree, unless forced by popular opinion?

Also, activists here are trying to act ahead of time to prevent embarrassing problems from arising. At the Occupy site in Freedom Plaza, for instance, “residents” are required to sign a form pledging not to carry weapons, use alcohol or illegal drugs, or vandalize or steal property. They promise to “respect quiet hours” from 11 p.m. to 7 a.m.

I watched late Thursday as one of the camp’s principal organizers, Kevin Zeese, calmly told an agitated, homeless man with alcohol on his breath that he couldn’t remain if he were drinking.

“With the homeless come homeless problems: mental illness, alcoholism, addiction,” Zeese said.

“This is a problem every Occupy has. What we’ve done is welcome anybody who is willing to become part of the community” and respect the rules, he said.

There are also efforts to marginalize anyone who might start trouble.

“In other cities, there were people more on the anarchist side,” said Drew Goldsmith, who belongs to five organizing committees at the McPherson Square camp. Washington has some anarchists, he said, but they’re nonviolent.

“We have some people who want to build bonfires in front of the White House. We need to separate ourselves from them,” Goldsmith said.

The camps naturally attract some troubled and troubling individuals. It’s a challenge to keep the sites clean, drug-free and peaceful. If the activists succeed, however, the rewards could be long-lasting.