In this July 22, 2015, file photo, Rep. Tim Huelskamp, R-Kansas, speaks during a House Veterans Affairs Committee hearing on Capitol Hill in Washington.

Topeka ? Republican U.S. Rep. Tim Huelskamp’s dissertation on congressional agriculture committees from 1995 is being used against him as he seeks re-election.

Huelskamp railed against New Deal-era agriculture subsidies and price supports in his 400-page essay as a Ph.D. student at American University in Washington, The Topeka Capital-Journal reported. Huelskamp said the subsidies “ignored the productivity advances in the industry, not to mention any semblance of economic reality.”

His opponent in the 1st Congressional District primary on Aug. 2, obstetrician Roger Marshall of Great Bend, has been critical of Huelskamp’s opposition to the 2014 farm bill and a government funding bill that renewed billions of dollars in crop insurance last December.

“Career politicians like Tim Huelskamp believe Congress ‘over-represents agricultural interests’ of rural Kansas,” Marshall said. “On the contrary, I believe maintaining a safe, reliable, affordable food source is not only a top economic priority, but also a top national security priority.”

Marshall was referencing a part of the dissertation in which Huelskamp, citing research from other scholars, said the House and Senate agriculture committees “over-represent rural and agricultural interests.”

Huelskamp called questions about his dissertation “outrageous.”

Another issue that’s emerged is Huelskamp’s removal from the House Agriculture Committee after he clashed with former Speaker John Boehner. Now a member of the influential House Steering Committee that coordinates committee assignments, Huelskamp said he anticipates returning to the committee after the November elections.

He touted his work as a fifth-generation farmer and accused Marshall of lacking hands-on experience.

“He is a doctor. He is not a farmer. He wears scrubs to work,” Huelskamp said.