If you think the Iowa caucuses don't affect you, you haven't been grocery shopping lately.

While you're at the supermarket, presidential contenders of all parties are shopping for votes in Iowa that you will pay for with higher prices on just about everything in your grocery cart.

That's because taxpayers are spending about $6 billion annually on federal tax credits, incentives and mandates promoting the conversion of nearly half of the Hawkeye state's corn crop to ethanol, a fuel additive of questionable value to energy and the environment.

Iowa is not only the leading producer of corn but it is also the leadoff state for selecting presidential nominees. And there's the rub. 

State officials and Big Corn want the pols to promise they won't let the Environmental Protection Agency lower the Renewable Fuel Standard (RFS) requirements for the ethanol content in gasoline. The subsidies should have been phased out long ago, but a parade of pandering politicians of all stripes have been promising Iowans to support RFS.  The reason is simple: they're buying votes for the first-in-the-nation Iowa Caucuses. 

It's an issue that makes for odd bedfellows.  Republicans Mike Huckabee, Rick Santorum and Donald Trump are on the same side of the issue as Hillary Clinton, while opposing subsidies are Bernie Sanders and Ted Cruz, who are otherwise political polar opposites.

The fear of $300-a-barrel oil in the midst of the Arab oil embargo in the early 1970s fueled the ethanol drive, leading to mandating that it comprise as much as 15 percent of the gasoline at the pump.  It was sold as a key to energy independence, but it long ago outlived any usefulness; today oil is below $50 per barrel.

There's more politics than science involved. The nation has achieved energy independence today, no thanks to ethanol. The greatest benefit of ethanol goes to Big Corn and corporate agriculture, not consumers.

Critics say it takes as much energy to produce as it provides.

Truckers say ethanol damages their engines and AAA says it is also bad for lawn mowers, weed eters boats and motorcycles. But most of all it raises food prices, notably Kosher food, and Iowa is a major producer.

A major portion of Iowa's corn crop goes for animal feed in a state that boasts two of the country's largest producers of Kosher and Halal meats.  The state has an estimated 6,200 Jews and 6,500 Muslims out of 3 million residents.

The increased demand for corn to produce ethanol and biofuels – consuming about 47 percent of the state's corn crop– has removed large amounts of corn from food production and driven up food and feed costs not just in the United States but in third world countries dependent on American exports.   

Israel, one of the world's biggest per capital consumers of corn, is an important and growing American customer.

Corn is our most ubiquitous crop.  It is in animal feed for the beef, chicken and other meats we consume, as well as in bread, cereal, candy, beer and whiskey, soft drinks, and a full range of foods plus pharmaceuticals, disposable diapers, glue, cosmetics and much more.

There are growing calls on Capitol Hill to repeal corn-related requirements and subsidies, but nothing will happen in this Congress or the next, especially if the 45th president embraces RFS while campaigning in Iowa between now and February 1. 

It's too early to count out Big Corn, as is you can see at your local grocery, especially at the meat counter.  It would help if presidential candidates spent more time doing the family shopping than making promises the rest of us don't need and can't afford.