JEFFERSON, Iowa — Elizabeth Warren routinely rips the Koch political network for allegedly thwarting efforts to combat climate change so it can protect the family's oil interests.

But the Massachusetts senator and 2020 Democratic presidential candidate blasted the network on Thursday afternoon for its role in stymieing research into more sustainable farming practices.

Regarding how she would stop the Koch network, which is now overseen by industrialist billionaire and Republican megadonor Charles Koch, from interfering in higher education, Warren said, "It's basically just one more turn of corruption, right?"

Warren, fresh off revealing her plan to stimulate the nation's rural economy, told a 250-person crowd gathered at a historic furniture shop that land grant universities and colleges in the Midwest were supposed to boost innovation in the agriculture sector. But she said tax cuts had provided private and corporate money with the opportunity to undercut the schools' "research mission."

"There were some good funders," she said. "But they were the ones who had an agenda, right? The ones who don't believe in climate science, the ones who want to support Big Ag, right? The ones who want to do pharma that helps Big Pharma, right?"

Warren referred to a farming family she met Thursday morning in Harlan, Iowa, who complained the institutions weren't addressing how they could "manage their land more cheaply and more sustainably, and still get good yield."

"He said there's just a twist in all of the research, and that in turn gets felt everywhere else in the system," she said, adding her anti-corruption platform included a plank requiring congressional witnesses to disclose who paid for their academic endeavors.

Charles Koch, longtime co-owner, chairman, and CEO of Koch Industries, is equally lauded and scorned for his support of free market-oriented educational and research organizations such as George Mason University and the Cato Institute.

The question wasn't the only curve ball thrown at Warren during the town hall. Another audience member asked the senator to change her campaign slogan, "Dream big, fight hard," because the word "fight" didn't encourage civil discourse.