In a social media post, the president called the move “just better” for American consumers, and also predicted “this will be a very good move by them,” referring to the Atlanta-based beverage giant.Trump revealed on social media that Coca-Cola has “agreed to use REAL Cane Sugar in Coke in the United States” after discussions between himself and company leadership. 

In a statement, a Coca-Cola company spokesperson said: “We appreciate President Trump’s enthusiasm for our iconic Coca‑Cola brand. More details on new innovative offerings within our Coca‑Cola product range will be shared soon.”

The change is significant—since the mid-1980s, virtually all Coca-Cola sold in the U.S. has been sweetened not with sugar, but with high fructose corn syrup, a less expensive alternative, but a very politically potent one.

The commercial production of high fructose corn syrup takes place in Iowa, the top corn-producing state in the U.S. It’s been a major product for agribusiness since the 1970s, with companies such as Archer Daniels Midland having key plants in Iowa. They are a big player in Washington, D.C., as is the “farm lobby,” which refers to a number of institutions that lobby on behalf of farmers’ interests. U.S. farm policy—shaped by the farm lobby—subsidizes corn heavily and imposes tariffs and quotas on imported sugar, making high fructose corn syrup the default sweetener for many U.S. food producers. All of these dynamics are reinforced by Iowa’s role in presidential politics, with the state being the first presidential caucus in the electoral calendar.

When did Coke switch to corn syrup?

Coca-Cola’s original formula, dating back to its 19th-century origins, used cane sugar as the sweetener of choice. That changed during a period of economic and regulatory upheaval in the late 1970s and early 1980s.

Faced with rising sugar prices, prompted in part by U.S. government quotas and tariffs on imported sugar alongside growing subsidies for domestic corn, Coca-Cola began blending corn syrup with sugar in its beverages. The transition was complete by 1984. Even after the “New Coke” formula controversy and the return of “Coca-Cola Classic,” the drink retained high fructose corn syrup as its sweetener, not sugar.

The cult of “Mexican Coke”

Coca-Cola in other countries—most famously in Mexico and across Europe—has continued to use cane sugar, spawning a cult following for “Mexican Coke” among U.S. consumers who preferred the original taste.

American soda fans have long claimed to notice a difference in beverages sweetened with cane sugar. Imports of “Mexican Coke,” made with real sugar, became a popular niche item, prompting limited edition “throwback” sodas using cane sugar to appear periodically.

It remains unclear how quickly Coca-Cola will phase in cane sugar nationwide, and it likewise remains unclear how this move fits within Trump’s broader use of tariffs, including the tariffs predating his tenure that make sugar imports more expensive than subsidized corn. But it’s a major change beyond just a beverage giant’s soda recipe.

Coca-Cola did not immediately respond to a request for comment. Fortune has also sent requests for comment to the American Farm Bureau Federation and the Iowa Corn Promotion Board.

For this story, Fortune used generative AI to help with an initial draft. An editor verified the accuracy of the information before publishing.