The arrests and occasional violence marking Occupy Wall Street's two month anniversary underscore Democrats' strategy of keeping their distance from the protest movement.
Democrats and Occupy Wall Street share similar concerns about economic inequality. But while the Republican Party and the tea party were a natural political pairing, Democrats have been reluctant to cast their lot with Occupy agitators who confront police and squat in public encampments.
Thursday's mass demonstrations in New York, Los Angeles and elsewhere were a stark reminder of why the Occupy movement remains a minefield for Democrats, even as polling continues to show public support for its message.
At least 175 were arrested as protesters attempted to block traders from entering the New York Stock Exchange in lower Manhattan. Police said four officers were injured when demonstrators threw liquid _ possibly vinegar _ in their faces.
The arrests came two days after hundreds were forcibly evicted from New York's Zuccotti Park, where the Occupy Wall Street movement was launched Sept. 17 when activists pitched tents to protest policies they said benefit only the wealthiest 1 percent of Americans.
Los Angeles police arrested at least 23 people after declaring an unlawful assembly at an Occupy rally in the city's financial district. In Portland, Ore., more than a dozen protesters were led away in handcuffs after attempting to barricade an entrance to the Steel Bridge, an important link for mass transit in the region.
For their part, many Occupy protesters have been openly contemptuous of Democrats including President Barack Obama, arguing that both political parties are equally beholden to corporate interests and responsible for enacting policies that have hurt the middle class.
But even without an explicit alliance between the two groups, many Democrats believe the Occupy movement's focus on income inequality could help the party reinvigorate its base.
"It's injecting energy and life into progressive ideas and values, and it's showing some weak-kneed Democrats they should be more aggressive on those issues," Steve Rosenthal, a Democratic strategist and longtime labor leader, said.
Republicans have largely dismissed Occupy Wall Street as a band of anti-capitalist ruffians, while trying to goad Democrats into embracing the movement or answering for its excesses.
Republican presidential candidate Mitt Romney has called the movement dangerous class warfare, while fellow candidate Michele Bachmann called the protesters "ignorant" and "disrespectful."
So far, Democrats have tried to have it both ways _ embracing the movement's economic concerns while steering clear of its rougher edges.
"I think people feel separated from their government," Obama told ABC News. "They feel that their institutions are not looking out for them."
The Democratic Congressional Campaign Committee has gone a step further, posting a petition, "100,000 Strong Standing With Occupy Wall Street," that blames Republican policies for the nation's economic discontent.
But many Occupy Wall Street activists contend they have no interest in helping Democrats.
"The Occupy movement is rooted in the idea that the political system is broken to such a degree that we can no longer work through the Republican or Democratic parties," Tim Franzen, a spokesman for Occupy Atlanta, said.
"This is not about politics. This is about people," said Marsha Spencer, an Occupy volunteer in New York. "We've lost our government. It's not by the people, for the people anymore. We need to get it back, and we don't need a political party to do that."
Such talk has frustrated some Democratic leaders, who say engaging in electoral politics would make the Occupy movement more effective.
"I want them to get up and start registering voters, start playing towards the 2012 election," former Pennsylvania Gov. Ed Rendell said at a seminar at Harvard University last week. "Not just the presidential, but congressional and Senate elections and state legislative elections. That's where they can make real change."
At least one candidate seems to be channeling the energy of the Occupy Wall Street movement: Democrat Elizabeth Warren, a Harvard Law School professor challenging Republican Sen. Scott Brown in Massachusetts.
Warren's campaign drew national attention after she said the rich should pay more in taxes since they have benefited the most from government policies. Warren later claimed to have laid the "intellectual foundation" for the Occupy movement but stressed that protesters need to obey the law.
Republicans recognized an electoral ally in the tea party movement soon after its inception in early 2009, when activists began protesting government spending and the federal bank bailouts.
While many tea party members claimed to be nonpartisan, they were mostly white, older and conservative and shared the Republican Party's goal of limiting government and cutting spending. Tea party activists helped drive many of the angry congressional town hall meetings protesting Obama's health care overhaul, and the sweeping Republican victories in the 2010 midterm elections were fueled in large party by tea party enthusiasm.
While the Occupy movement has not had similar tangible goals, activists say it has already had an impact on the political dialogue.
Labor leaders say the movement's message of economic inequality was a factor in Ohio, where voters overwhelmingly repealed a law curtailing public employees' right to collective bargaining. And some are crediting the movement with successfully pressuring Bank of America to drop its plan to charge customers a $5 monthly fee to use their bank cards.
Associated Press writers Erika Niedowski in Providence, R.I., and Leonard Pallats in Atlanta contributed to this report.