With the Iowa caucuses less than two weeks away, here’s a newsflash: The corn-ethanol mandates, which are always a pivotal issue in that state, are more deadly than the emissions from those cheating Volkswagens. Four times more deadly, to be precise.

Corn ethanol mandates are more than four times as deadly to the American public as the VWs. Yet the front-runners for the presidency are marching in lockstep in favor of ethanol.

By now, most Americans are probably aware that Volkswagen AG, the world’s second-largest automaker, is facing legal woes both in the U.S. and abroad for installing software on its cars that allowed the vehicles to defeat emissions-control tests. Two weeks ago, the Justice Department filed a lawsuit against the German company for violating the Clean Air Act by outfitting more than half a million cars with the software. In the U.S. alone, VW could face fines of as much as $90 billion.

The vehicles in question produced 10 to 40 times more nitrogen oxides than the law allowed. And those increased emissions will cause about 60 premature deaths a year in the U.S., according to a study by researchers at MIT and Harvard University.

Shortly after it was discovered that VW had been cheating, Cynthia Giles, the Environmental Protection Agency’s assistant administrator for the Office of Enforcement and Compliance Assurance, denouncedthe company's effort to “evade clean air standards” as “illegal and a threat to public health.”

But corn ethanol is an even bigger threat, as the EPA's own research shows. In 2010, the agency detailed the environmental and economic effects of the Renewable Fuel Standard, the federal mandate that requires retailers to blend ethanol into the gasoline they sell. Adding ethanol to gasoline causes higher emissions -- including nitrogen oxides, the same pollutants at issue in the VW case.

Ethanol-blended fuel also increases “emissions of hydrocarbons, nitrogen oxides, particulate matter and other pollutants,” the EPA found, and that will “lead to increases in population-weighted annual average ambient PM [particulate matter] and ozone concentrations, which in turn are anticipated to lead to up to 245 cases of adult premature mortality.”

Thus, the corn ethanol mandates are more than four times as deadly to the American public as the VWs. Yet the front-runners for the presidency are marching in lockstep in favor of ethanol. Indeed, their nearly unanimous support for the mandate is like no other issue in American politics. The reason for their fealty to Big Corn is obvious: No presidential candidate has ever won the Iowa caucuses while opposing corn ethanol.

Donald Trump, a leading Republican candidate in Iowa, has said “Ethanol is terrific … I am totally in favor of ethanol, 100 percent. And I will support it.”

Hillary Clinton, the Democratic front-runner in Iowa, is also an ethanol booster. Never mind that as a U.S. senator, she voted against ethanol 17 times. Last August, she said, “We need to strengthen the Renewable Fuel Standard” and expand “the overall contribution that renewable fuels make to our national fuel supply.”

The only current candidate who has dared stray from ethanol orthodoxy has been Ted Cruz, but even he is backpedaling. About two weeks ago, he published an op-ed article in the Des Moines Register saying it was “utter nonsense” that he was opposed to ethanol.

While it may be too much to hope for bravery among presidential candidates during their quadrennial pilgrimages to the Hawkeye State, the EPA should be protecting the public from ethanol, not promoting it. Alas, that’s just what the agency is doing. In November, despite its own findings that ethanol-blended fuel is resulting in the premature death of more than 200 Americans per year, the agency actually increased the amount of ethanol that must be blended into domestic fuel supplies each year by more than 1 billion gallons.

If the federal government is going to fine Volkswagen billions of dollars for knowingly increasing air pollution, it should take similar action against the corn ethanol industry. Better yet, the EPA should eliminate the ethanol mandate.

This piece originally appeared in Bloomberg View