NEW YORK – New York’s budding anti-capitalism protest movement began last month with a vague sense of grievance over the widening gap between the rich and poor in America.

But in three weeks, it has provided fuel for a broader national anti-corporate message, drawing inspiration from the Arab Spring but struggling to define its goals beyond a general feeling that power needs to be restored to ordinary people.

Similar protests are springing up in Boston, Los Angeles and Chicago, and organizers in Washington plan a march Thursday at Freedom Plaza to “denounce the systems and institutions that support endless war and unrestrained corporate greed.”

On Monday morning, the scene at the heart of the Occupy Wall Street movement — Zuccotti Park, two blocks from Wall Street — had the feeling of a street fair, with women in colored wigs playing with hula hoops.

Protesters wearing white face paint with streaks resembling blood at their lips conducted a “zombie parade” down Broadway to underscore what they see as the ghoulish nature of capitalism.

Despite having no single leader and no organized agenda, the protesters insist they are on the verge of translating their broad expression of grievance into a durable national cause.

“The criticism has focused on the lack of cohesion in our message and demands,” said Arthur Kohl-Riggs, 23, a political activist from Madison, Wis. But what the critics don’t understand, he said, is “the value of forming a direct democratic movement” that is not controlled by political elites.

The protests have drawn an assortment of anarchists, anti-globalization activists and disaffected 20-somethings. But the efforts have also drawn support from union members, including New York transportation workers who let some protesters take shelter inside the subway system.

Brought together by social media outlets such as Twitter and Facebook, participants hope the New York protests can plant the seeds of a permanent national movement.

The primary theme is that corporate capitalists, backed by corrupt politicians, have tipped the balance of the economic system too far in favor of the powerful, condemning the regular guy to debt and little opportunity. As a sign put it: “The loan shark ate my world.”

The movement got a seal of approval Monday from one of the world’s most successful capitalists, billionaire George Soros, who said the demonstrators had every reason to be angry at the U.S. financial system for jeopardizing their future.

“I can sympathize with their grievances,” Soros said, faulting U.S. banks for driving small businesses out of existence by boosting credit charges to unsupportable levels.

Minnesotan Jay Benson, 25, said he drove to New York several days ago with a friend to participate in the protests. A forklift operator whose father worked for 35 years at the same railroad job, Benson voiced frustration at the piecemeal jobs he’s had to take to make ends meet. “One week I get 34 hours; the next week I’d have 12,” he said.

Not everyone was impressed.

Christopher Dilmer, 44, a steamfitter who works at the World Trade Center site, said, “I don’t know what they are protesting,” noting that everyone seemed to want something different.

He said he’s not disputing that the country’s “economy is in the tank,” but he thinks most of the young protesters could find work if they put their mind to it.