This Protest Rally Is Brought to You by Big Soda

— -- Grassroots protest rallies are a dime a dozen in San Francisco, but it’s rare they have corporate sponsorship.

That’s one thing that suggests The Coalition for an Affordable City may not be what it seems.

The Coalition for an Affordable City is not dedicated to fighting San Francisco’s soaring rent costs or rampant gentrification, or any of the countless other economic traumas resulting from the city by the Bay’s reinvention as the capital of the new digital economy.

Nope, the Coalition for Affordable City has other priorities. The group has spent more than $9 million to defeat a single item on Tuesday’s local ballot in San Francisco. Proposition E would impose a tax on sugary drinks -- $0.02 per ounce -- and earmark the proceeds for programs to educate children about healthier lifestyle choices as part of a city effort to reduce childhood obesity.

“The Coalition for an Affordable City is a fake AstroTurf front group of the American Beverage Association, which is funded largely by Coca-Cola and Pepsi, Dr. Pepper, Red Bull and Sunny D,” said San Francisco Supervisor Scott Weiner, one of the authors of Prop E.

Bay Area writers and bloggers have accused the “No on E” campaign of creating the illusion of community support by hiring people to hold signs at their rallies -- even people who don’t live or vote in San Francisco. Our team decided to look into it. When a "Nightline" producer found a Craigslist ad looking for paid sign holders in the San Francisco Bay Area, she called and asked about the job. A staffer from the “No on E” campaign told our producer that the job paid $13 dollars an hour and that it didn’t matter that she lives in New York. The campaign offered her the job.

Indeed the primary financial backer of the No on E campaign is the American Beverage Association, the soda and beverage industry’s powerful lobbying arm.

“We’re basically saying that taxing grocery items is the wrong approach,” said "No on E" spokesman Roger Salazar. Salazar insists the group is not in any way trying to conceal its connection to the industry.

“It’s not a front group,” Salazar said. “There isn’t any secret about it. It’s really not the issue. The main issue is, is the measure right for San Francisco and we don’t believe it is.”

Salazar claims the group has a city-wide coalition of small business owners who disapprove of what is known as the soda tax.

“We have over 1,000 businesses that have signed up as part of the coalition,” Salazar said. “We don’t think that it's the government's place to tell us what we got to be eating and drinking. It’s not their choice, it’s ours.”

But some of the businesses listed on the coalition’s “No on E” endorsement list told “Nightline” they actually support Prop E.

Sam Ong, the owner of Smoking Warehouse Barbeque in Potrero Hill, said the “No on E” campaigners told him the proceeds from the tax may not go to the intended childhood health programs. But when told that was false, and the tax dollars are actually earmarked for child health education, he said, “then I’m for it.”