Trump USDA nominee faces pushback over lack of experience Trump nominated Sam Clovis to serve as the USDA's chief scientist.

 -- A former co-chairman of Donald Trump’s campaign was nominated last month as the chief scientist at the United States Department of Agriculture, a decision that has been met with pushback ahead of his forthcoming confirmation vote.

President Trump chose Sam Clovis, who is currently serving as a senior White House adviser to the USDA, as his nominee for undersecretary of agriculture for research, education and economics.

As the department’s chief scientist, Clovis would be responsible for overseeing the Agricultural Research Service, the Economic Research Service, the National Institute of Food and Agriculture and the National Agricultural Statistics Service.

However, Clovis’ experience and past controversial statements have led some to criticize Trump’s decision to nominate him for the position.

According to biographical information provided by the White House in a press release announcing his nomination, Clovis received an undergraduate degree in political science and spent 25 years in the U.S. Air Force, including as a pilot. He later obtained an MBA and a Ph.D. in public administration and served as an economics professor at Morningside College in Iowa.

In 2010, he began hosting a talk radio show in Iowa and eventually left his position at Morningside to run for office himself.

In 2014, a year in which he lost both a bid for the Republican nomination for U.S. senator in Iowa and the election for Iowa state treasurer, Clovis gave an interview to Iowa Public Radio in which he responded to a question about scientific conclusions on climate change.

"I am extremely skeptical," said Clovis. "I have looked at the science and I have enough of a science background to know when I’m being boofed. And a lot of the science is junk science. It’s not proven; I don’t think there’s any substantive information available to me that doesn’t raise as many questions as it does answers. So I’m a skeptic."

Clovis was Trump's national campaign co-chairman and senior policy adviser in 2015 after leaving former Texas Gov. Rick Perry’s failed campaign for president.

Prior to joining Trump's staff, Clovis questioned the real estate mogul's religious beliefs and criticized his performance at a primary debate in emails later obtained by ABC News.

"Of all the potential candidates who spoke, one of them left me with questions about his moral center and his foundational beliefs," Clovis said in the emails.

According to CNN, in a 2012 blog post Clovis expressed support for the false claim that President Obama wasn't born in the U.S. He also called former Attorney General Eric Holder a “racist black” during a 2013 episode of his radio show.

Moreover, CNN reported that Clovis once argued that homosexuality and “LGBT behavior” is a choice and that “if we protect LGBT behavior, what other behaviors are we going to protect? Are we going to protect pedophilia?”

Senate Minority Leader Chuck Schumer, D-N.Y., and Sen. Brian Schatz, D-Hawaii, argued in a joint statement that Trump should withdraw Clovis’ nomination because of the “racist conspiracy theories he has stoked.”

“First and foremost, President Trump should withdraw the Clovis nomination immediately -- not only because he is a proud ‘skeptic’ of climate change and wildly unqualified for the position of USDA Chief Scientist –- but also as a gesture to the American people that this administration is serious about rooting out the most hateful voices in our society,” Schumer and Schatz said in the statement.

The two Democratic senators also added that they would “vehemently oppose” Clovis’ nomination.

Debbie Stabenow, ranking member of the Senate Agriculture Committee, said in a statement that Clovis “seems to lack the necessary agricultural science and research qualifications that are required by the Farm Bill.”

Clovis’ nomination does have the support of Secretary of Agriculture Sonny Perdue and Iowa Sen. Chuck Grassley, a Republican member of the Senate Agriculture Committee.

ABC News has reached out to the White House for comment.

Catherine Woteki was the most recent undersecretary of agriculture for research, education, and economics, serving from September 2010 until January of this year. Woteki previously led scientific affairs for the food conglomerate Mars, was the dean of agriculture and a nutrition professor at Iowa State University and held positions in the USDA and White House Office of Science and Technology Policy.

ABC News' Katherine Faulders contributed to this report.