By Lance Williams, Reveal

In the final months of 2014, the nation’s plastic bag manufacturers spent $3.1 million to sidetrack a California law that sought to ban throwaway bags.

But that political spending spree may be a small down payment on what could be a hugely expensive environmental fight on the state ballot in 2016 – and one with profound national implications as well.

Last year, the California Legislature barred retailers from giving plastic shopping bags to consumers. A dozen bag manufacturers – most from outside the state – banded together to finance a quick-strike petition challenging the law before it had gone into effect.

The bag companies gathered some 800,000 signatures – enough to put the issue of whether California should ban the bags to a statewide vote. Until the November 2016 election, the new law remains in limbo.

The biggest bag manufacturers are based in South Carolina, Texas and New Jersey. But starting in 2010, the industry emerged as a free-spending political player in California’s Capitol, pumping about $6 million into donations and lobbying since then.

That’s a measure of how eager the industry is to stop California from enacting what would be the first statewide ban in the country.

With the referendum looming, the price could get quite a bit steeper.

The cost of running a statewide ballot measure spirals upward every election. Four winning campaigns spent an average of $34 million in 2014, according to a recent analysis by Forward Observer, a Sacramento political consulting firm.

Meanwhile, a Los Angeles Times poll showed that 60 percent of Californians support the bag ban.

Given those numbers, overturning the ban will be a “heavy lift” for the industry, said Renee Van Vechten, a professor of political science at the University of Redlands and an expert on state initiatives. Even extraordinarily heavy spending might not make a difference, she said.

“Is it winnable? The easy answer would be no,” she said. “But they obviously think they have a chance and a lot to lose if it goes forward.”

The campaign’s cost likely will be shouldered by the same companies that financed the petition drive. Here, from state records, are the petition donors:

Throwaway bags are a staple of America’s convenience lifestyle, but environmentalists complain that they are a huge source of litter and pollution.

Californians throw away 14 billion bags per year, the state Legislative Analyst’s Office said. Estimates of cleanup and disposal costs range from $25 million to $500 million, and a huge number of bags don’t make it to the landfill.

But the industry contends that the rationale for banning plastic bags is based on “emotional imagery, junk science, and exaggeration, rather than facts and good data,” as Phil Rozenski, policy chair for the American Progressive Bag Alliance, wrote in an email.

Bag bans threaten the livelihood of 30,000 American workers, he wrote. Instead of a job-killing ban, California should pursue “comprehensive recycling education and in-store take back programs,” he wrote. He also called California’s law “a scam” and said the industry believes voters will vote to repeal it.

For years, environmentalists concentrated on backing local ordinances to ban throwaway plastic bags. San Francisco was the first to enact a ban, in 2007. Today, advocates say more than 100 California communities and dozens more around the country have such laws on the books.

The push for a statewide ban began in 2010, recalled Los Angeles activist Hans Johnson, but it ran into a furious and well-financed lobbying campaign. From 2010 through 2014, South Carolina-based Hilex Poly Co. spent $1.8 million lobbying the California Legislature, records show, far more than it spent in any other state. The American Progressive Bag Alliance, the industry’s Washington, D.C.-based political arm, spent an additional $1 million.

Hilex also donated more than $500,000 to about 70 state lawmakers and political committees in California, favoring Democrats, who controlled the Legislature, by about 2 to 1. The top recipient lawmaker was state Sen. Leland Yee, D-San Francisco, who was indicted last year in an FBI bribery sting. Hilex gave $9,800 to then-state Sen. Alex Padilla, D-Van Nuys, now the secretary of state and the author of the bag ban measure that was enacted in 2014.

While the bill was pending – and Padilla was in a tight race for secretary of state – the bag alliance paid for a flurry of television and radio ads criticizing what it called “Padilla’s misguided bag ban.” A lobbying report indicates that the alliance spent $266,000 on the ad campaign.

Top donations from Hilex Poly Co. in California, 2010-2014: