Sen. Bernie Sanders sent out an email to supporters Friday asking them to take action against a Senate bill that would overturn Vermont’s recent legislation requiring companies to label products containing genetically modified organisms.

“The corporate interests are at it again,” Sanders wrote. “Monsanto, agribusiness and the bio-tech industry have spent hundreds of millions of dollars trying to overturn legislation passed by Vermont, Connecticut, Maine and Alaska that calls for the labeling of GMO food. In fact, they are moving aggressively now because Vermont’s strong law goes into effect today.”

As the debate over GMOs wages on, the forces pushing for increased use of GMOs continue to spend an incredible amount of money on a marketing blitz to recruit more voices sympathetic to their cause. And if some of the tactics employed by the agrichemical industry seem like something out the Sterling Cooper Draper Pryce advertising agency, well, that’s because they are.

In an article for the Huffington Post, Carey Gillam, a former business reporter for Reuters who later began working for U.S. Right to Know (a nonprofit largely funded by the Organic Consumers Association), describes the pressure she felt from Monsanto and other Big Ag companies to jump on the GMO train:

Pressure from Monsanto began when I first started covering them around 1999 or 2000, and it wasn’t even GMO crops. At the time Monsanto was in transition from an industrial chemical company involved in litigation with PCBs to an agrichemical and biotech seed company. They had some GMO crops but they had only been out a few years. They also had the pesticide glyphosate or Roundup, and they were marketing bovine growth hormone for dairy cows. There were a lot of questions about a lot of this stuff.

While logical people can debate the positives and negatives of GMOs, the company behind many of Big Ag’s pro-GMO ads raises serious questions about the campaign’s credibility.