President Donald Trump is one of the rarest of all creatures — a politician who keeps his promises.

Sick of politicians making grandiose campaign promises, only to discard them after the election, the American people shocked the world by electing a billionaire businessman and political novice in Trump, hoping that he, not beholden to special interests, would battle entrenched politicians and bureaucrats who wield enormous power in the DC swamp.

Trump, from a conservative perspective, has excelled beyond all expectations, slashing massive amounts of economy-crushing regulatory red tape, opening the throttle on American energy production, creating a pro-growth economic environment, pulling us out of or reworking bad trade deals, and making American sovereignty and prosperity the yardstick by which policies are measured.

Unfortunately, not every promise kept is a good thing, as evidenced by reports this week that Trump is giving a sop to the ethanol/corn industry, issuing a waiver for summer restrictions on E15 (15% ethanol/gas blend) fuel, paving the way for year-round use.

This move is entirely political. In fact, after the announcement, Trump held a MAGA rally in Iowa, and that was no coincidence. Between helping Iowa Republicans in the election and heartland farmers hurt by Trump’s own tariffs, the political ramifications are significant, so this decision is, sadly, hardly surprising. For the American people, however, the benefits of expanding this boondoggle are dubious at best.

Last year, when former EPA Director Scott Pruitt announced rollbacks to the ethanol mandate, the response was swift and forceful. Sen. Chuck Grassley (R-IA), chairman of the Senate Judiciary Committee, issued a not-so-veiled threat to President Trump that the move would have consequences; namely, seeing his judicial nominees move through Grassley’s committee at the speed of molasses. Trump got the message, and the changes were put on hold.

Grassley however, has held up his end of the unspoken deal, deftly ushering Trump’s Supreme Court nominee, Judge Brett Kavanaugh, through a vicious confirmation process that made the Democrats’ reprehensible “high-tech lynching” of Justice Clarence Thomas seem downright neighborly by comparison.

Additionally, this ethanol decision may be the help needed to get Iowa’s Republican governor, currently trailing her Democrat opponent in the polls, and at least two at-risk Iowa House members, over the finish line to victory. These wins would be critical when many are predicting a Democrat takeover of the House and Senate.

As for the ethanol change itself, it’s unlikely that it will take immediate effect. A lawsuit is planned that challenges the legality of the waiver. Additionally, a bipartisan letter from 20 members of Congress from oil-producing states went to President Trump last week, opposing the measure, arguing it would do nothing to protect refinery jobs and would actually harm American consumers.

And they are right.

The ethanol mandate his been a huge victory for Midwestern agricultural states, which are essentially guaranteed a buyer for every ear of corn they can grow, and then some.

Unfortunately, from a scientific and environmental standpoint, the mandate is a disaster. Ethanol harms gasoline engines, eating through seals, gumming up fuel systems, damaging tanks, and introducing stray moisture into the system. This leads to thousands of dollars of unnecessary repairs for consumers.

Ethanol is 33% less energy dense than gasoline — meaning you have to burn 33% more ethanol to travel the same distance — and ethanol is dirtier than gasoline, generating significantly more formaldehyde, creating twice as much ozone smog.

Investor’s Business Daily asks, “Do people want ethanol in their gasoline so badly they’re willing to pay extra for something that cuts their fuel efficiency by anywhere from 5% to 7% per mile?”

Then there is the destruction to the environment caused by clearing millions of acres of land for corn production. In the year 2000, only 5% of America’s corn crop went to ethanol production. By 2013, that had skyrocketed to 40%. To envision what a boondoggle the ethanol mandate is, consider that the amount of corn required to fill a truck’s 26-gallon gas tank would feed a person for an entire year!

A 2009 Duke University study found that growing corn for fuel production actually produces more CO₂ than it saves. The Associated Press, in an in-depth investigation of the “green” energy industry entitled “The Secret, Dirty Cost of Obama’s Green Power Push,” concluded:

The ethanol era has proven far more damaging to the environment than politicians promised and much worse than the government admits today. As farmers rushed to find new places to plant corn, they wiped out millions of acres of conservation land, destroyed habitat and polluted water supplies. …

Five million acres of land set aside for conservation — more than Yellowstone, Everglades and Yosemite National Parks combined — have vanished on Obama’s watch. Landowners filled in wetlands. They plowed into pristine prairies, releasing carbon dioxide that had been locked in the soil. Sprayers pumped out billions of pounds of fertilizer, some of which seeped into drinking water, contaminated rivers and worsened the huge dead zone in the Gulf of Mexico where marine life can’t survive. The consequences are so severe that environmentalists and many scientists have now rejected corn-based ethanol as bad environmental policy. But the Obama administration stands by it, highlighting its benefits to the farming industry rather than any negative impact.

President Trump has done much right since taking office, but this is a decision he needs to reconsider.

It’s also an area where bipartisan agreement — between limited-government, free-market advocates on one side, and environmentalists on the other — could be found and, who knows, maybe even generate enough goodwill to find common ground on other issues.

King Corn has ruled politics long enough. It’s time for a coup.