Environmental groups once strongly supported the federal government’s sweeping ethanol mandate in the Renewable Fuel Standard over a decade ago, touting the fuel additive as a potential cure for the supposed climate crisis.

Ten years later, these same groups are backing proposed Republican reforms to these regulations.

The intense opposition to the RFS from environmental and conservation groups comes as the White House and congressional leaders work to craft the most serious reforms the program has seen since it was established more than 10 years ago. As Republicans and oil-industry groups bemoan the RFS as a job killer in the oil refining sector, environmentalists say their once-high hopes that ethanol could reduce carbon emissions, preserve land and help fight climate change have been proven wrong.

“The road to hell is paved with good intentions,” said Collin O’Mara, CEO of the National Wildlife Federation, a group that was once a vocal supporter of the RFS but now has become one of its chief opponents. “There’s a reason why [the RFS] was bipartisan, but the problem is that the law hasn’t been followed … We’ve distorted both our energy policy and our natural resources. That absolutely could’ve been avoided.”

Texas Senator Ted Cruz has been working hard for these reforms, which are pitting the oil industry against the corn industry.

Sen. Ted Cruz, a Republican opponent of both ethanol subsidies and the Renewable Fuel Standard from oil-rich state of Texas, held up confirmation of a U.S. Department of Agriculture undersecretary for months until he secured a White House meeting on the issue.

Last week, Cruz and three other senators from oil and corn states met with White House officials to attempt to strike a deal on some administrative reforms. Another meeting was held with the oil and biofuels industries, including representatives from two ethanol and biodiesel facilities that have received at least $24 million in taxpayer subsidies from 2009-16 through the Department of Agriculture’s Bioenergy Program for Advanced Biofuels.

Additionally, President Donald Trump tried to help negotiate a deal between the two industries during the White House meeting.

Trump told the gathering of lawmakers and corporate executives that he supports a proposal from the refining industry to cap the price of biofuels blending credits that refiners must acquire to comply with the RFS.

Prices for the blending credits – which refiners must either earn or purchase – have surged in recent years, upsetting companies that in some cases are spending hundreds of millions of dollars on them.

The source, who asked not to be named because he is not authorized to speak publicly on the discussion, said Trump also expressed support for expanding sales of high-ethanol gasoline – a tweak long-sought by ethanol producers.

The environmentalists’ complaints related to the RFS standard are the rules rely too heavily on corn and not enough on other renewable fuel options. EPA head Scott Pruitt angered these groups, once again, by proposing a more conservative approach to setting annual biofuel blending volume requirements instead of enforcing technologically questionable green mandates.

The proposal is “consistent with market realities focused on actual production and consumer demand while being cognizant of the challenges that exist in bringing advanced biofuels into the marketplace,” Pruitt said in a statement.

The agency would keep the 2018 target for conventional ethanol at 15 billion gallons, unchanged from 2017, and set the requirement for advanced biofuels, including cellulosic ethanol, at 4.24 billion gallons.

These latest volumes confirmed an earlier Reuters report for volumes well below the 26 billion gallons of renewable fuels outlined by Congress in 2007.

However, no matter what reforms occur, it is doubtful that the environmental activists will appreciate Trump’s negotiating style.