Tannen Maury / EPA

Members of National Nurses United rally in Daley Plaza on Friday, ahead of the NATO Summit in Chicago.

A coalition of nurses’ unions is calling for a “Robin Hood” tax on Wall Street, which they say could generate up to $350 billion a year, in the first major protest ahead of this weekend’s NATO summit in Chicago.

Their pitch: impose a tax of 50 cents on every $100 of trades of stocks, bonds, dividends and other financial transactions, which are not currently taxed. The U.S. would join more than a dozen other nations that already have a financial transaction tax, according to National Nurses United (NNU).

"I've been asked many, many times ... 'What are you doing here as nurses? ... What do you have to do with the economy?'" Karen Higgins, a registered nurse and co-president of NNU, said to the crowd in Chicago's Daley Plaza.  

"We're watching this every day. We're watching patients suffer," she said, noting that nurses were seeing people without insurance or others who can't afford their co-pays, as well as a spike in the number of children with adult diseases due to eating poorly because their parents can't afford healthy food. "This is serious and in some cases it is actually deadly."

Storify: Scenes from the NATO summit protests

"We know the solution .. we are watching and seeing Wall Street throwing our money away as we see people suffer and die. It will not continue," she said. "We pay sales tax. It is time for Wall Street to start paying back what they owe the rest of the country and they need to pay sales tax."

The nurses’ call echoes last fall’s outcry by the Occupy Wall Street protesters over income equality, corruption and corporate greed. Proceeds from the Wall Street tax would support social services, education and healthcare.

The financial transaction tax is not a new concept. The U.S. had one from 1914 to 1966, and several politicians called for another one after the Wall Street crash in 1987, National Nurses United said.

Supporters include Nobel Laureate economists Paul Krugman, a New York Times columnist, and Joseph Stiglitz, the former World Bank chief economist -- both of whom have spoken out in favor of such a tax in the past.

A bill introduced last November by two U.S. Democratic lawmakers, Sen. Tom Harkin and Rep. Peter DeFazio, calls for a tax of 0.03 percent -- or 3 cents on every $100 -- on most non-consumer financial trading including stocks, bonds and other debts. It would raise more than $43 billion a year, according to DeFazio's office, which cited analysis from Congress' Joint Committee on Taxation.

Others, however, are against what has been called a “sin” tax on Wall Street.

“Our research shows unambiguously that higher trading costs depress the prices of stocks and bonds,” business school professors Yakov Amihud and Haim Mendelson  wrote in a Wall Street Journal op-ed. “A transactions tax will end up punishing Main Street, hurting the economy and reducing U.S. Treasury revenues in the next few years. It will thus exacerbate the effects of the financial crisis.”

The tax proposal protesters were initially targeting the G8 summit of global financial leaders that starts today. But when that meeting was moved from Chicago to Camp David in Maryland, they opted to carry on their demonstrations here anyway to take advantage of the large number of protesters converging on the city for the NATO summit.

Mary O'Sullivan, 72, came to the protest with her husband Chris Fogarty, 77. The retired married couple each held a sign, one reading "Honk To Indict Banksters" and the other "Stop Gov't Crimes."

"We're hoping that even at this late date the government will recognize that there is so much pain and suffering amongst the people that they will at least start paying attention," O'Sullivan said, noting she had recently spoken with a woman at a city mental health care facility that's being closed down. "She has no idea where she is going to go or how she is going to get there, and in the meantime, we're spending millions of dollars on drones to kill people."

Earlier this week, protesters demonstrated against the shuttering of local schools and mental health clinics, the loss of homes through foreclosures, and environmental issues surrounding the controversial “Tar Sands” pipeline, and they stormed the building that houses the headquarters of President Obama’s campaign.

Nam Y. Huh / AP

Demonstrators rally against the Keystone Pipeline and the Alberta Tar Sands outside of the Canadian Consulate in downtown Chicago on Thursday.

The city has assigned 3,100 officers plus hundreds from other cities to guard against the kind of violence that broke out in the streets of Seattle at the World Trade Organization meeting in 1999, NBCChicago.com reported, and officials have warned of massive travel disruptions.

They’ve also imposed limits on how close the protesters, which include dozens of unions and anti-war, environmental, education, healthcare and civil liberties’ groups, can get to the convention center where the summit is being held -- within “sight and sound” of it, according to the Chicago Tribune -- raising the ire of the demonstrators.

The National Lawyers Guild, which is sending out legal observers to the demonstrations and aiding those who are detained, said late Thursday that at least 20 people have been arrested so far this week. Occupy Chicago said 11 arrests occurred Wednesday night at an area home – though it’s not clear if those 11 were included in the guild’s tally. 

Organizers expect the biggest crowds at a rally led by anti-war activists on Sunday, in which a group of 9/11-era veterans plan to return their service medals to protest the "war on terror."

Todd Gitlin, a former leader of the 1960s-era group Students for a Democratic Society and a Columbia University sociology and journalism professor, said the Wall Street tax was an obvious focus for protesters.

“It’s concrete. It might be winnable. It has global resonance because you’ve got  … several national governments in Europe that support it,” he said, noting that it clearly distinguishes between the 99 percent and the 1 percent, and had an “intrinsic fairness” about it. “It’s a reform that rings sensible to large numbers of people but a lot of work has to be done… . Most people right now I think don’t get it.”

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