As voters in Oregon, California, Hawaii and Colorado prepare to weigh in on whether genetically modified organisms, or GMOs, should be banned or regulated in their states or communities, grassroots campaigns are being overwhelmed by millions that agrochemical and food industry titans are pouring in to defeat such measures.

Monsanto alone spent roughly $14 million in various local races this election year.

According to reports filed with the Hawaii Campaign Spending Commission on Monday, Monsanto has put over $5 million dollars into the campaign against a citizen-led Maui County ballot initiative to ban GMOs on the island. The measure, titled the Maui County Genetically Modified Organism Moratorium Initiative, stipulates that only until a comprehensive environmental and public health survey concludes that the cultivation of GMOs is safe and harmless can agrochemical companies continue to plant and test GMO seeds on the Hawaiian island.

Monsanto is the largest donor to the group Citizens Against the Maui County Farming Ban (CAMCFB), which opposes the moratorium. Despite billing themselves as a "citizens group," as of October 10, CAMCFB has raised nearly $8 million in donations, the vast majority of which was paid by Monsanto and Dow AgroSciences—both of which own large operations on the island that will be affected by the legislation. In contrast, supporters of the ballot initiative have raised less than $90,000 in donations from residents, local businesses and a crowd-sourced online fundraising campaign.

Big Ag's fight to suppress GMO legislation has become a routine narrative in campaign seasons. In 2012, the world's six leading pesticide makers spent over $20 million to defeat Proposition 37 in California, with Monsanto leading the way with over $8 million in donations. And again in 2013, outside industry groups spent over $22 million to defeat Washington's proposed labeling initiative.

However, according to Honolulu Civil Beat, CAMCFB's war chest is unprecedented in Hawaiian politics. "This is historic," Tony Baldomero, associate director of the Hawaii Campaign Spending Commission, told Civil Beat. "This is the highest (amount raised) that I have ever seen since I have been here, by any candidate committee, ballot issue committee, non-candidate committee, even super PAC."

In Oregon, a 2014 ballot initiative to label food items produced with or containing GMOs has become the costliest ballot contest in state history. As of October 18, the No on 92 Coalition reported raising $11.1 million in donations from Monsanto and other industry donors, including Big Food multinationals such as Coca Cola, Kraft Foods and Pepsi Co..

In that race, campaign donations have resulted in a slew of television advertising against the measure which, according to recent polls, may be having a significant impact on voter opinions. A June poll by DHM Research along with Oregon Public Broadcasting found that 77 percent of residents supported the measure. That number dwindled to 49 percent in DHM's follow up poll in October.

A Colorado labeling initiative, Proposition 105, has faced similarly well-funded opposition. Democracy Now! reported on Tuesday that, by some counts, money raised by the No on 105 group "nearly tripled" that raised by the Colorado Right to Know campaign. According to nonprofit farm policy research group the Cornucopia Institute, as of October 23, Monsanto alone has poured $8,836,650 into campaigns opposing Colorado's Proposition 105 and Measure 92 in Oregon.

As author and activist Michele Swenson notes in a Tuesday op-ed for Huffington Post, between 2012 and mid-2014, this "David (the people) vs. Goliath (giant corporations) struggle over GM food labeling" has unleashed a total of $100 million in spending by Monsanto and industry lobby group, the Grocery Manufacturers Association (GMA), to block GMO labeling in campaigns across the country.