DAVENPORT, Iowa — Taking aim at Florida Gov. Ron DeSantis Monday, former President Donald Trump told the crowd at a jampacked rally here that he will "protect Iowa ethanol from anyone who wishes to destroy it."

DeSantis, who made his first visit to the state as a prospective presidential candidate Friday, often voted as a member of Congress to restructure or slash subsidies for agricultural products, including ethanol.

Using nicknames — "DeSanctis" and "DeSanctimonious" — Trump said DeSantis "fought against it at every turn, and he’s going to do that again."

The comments were some of Trump's most direct public remarks against DeSantis, who is shaping up to be his chief rival for the GOP presidential nomination. Trump also slammed DeSantis again for voting to restructure Medicare and Social Security.

Iowa is one of the country's top-producing farm states, and Trump trumpeted his record on the issue from behind a lectern at the Adler Theater. Trump recounted providing payments to farmers to offset the costs of a trade war with China, reminded voters that he rolled back an Obama-era Waters of the United States rule that specifies which waterways are subject to Clean Water Act standards, and promised to do more.

"Within hours of my inauguration, I will cancel every Biden policy that is brutalizing our farmers," Trump said, prompting a standing ovation and a chant of "U-S-A" with his call to repeal President Joe Biden's agriculture agenda. Then he vowed to make fertilizer cheaper and to export more ethanol.

Trump, who spoke to a crowd much larger than those at two DeSantis events last week, said he chose the indoor arena because it was too cold outside for one of his trademark rallies.

This article was originally published on NBCNews.com