Senate Democrats said Wednesday they would “vehemently oppose” the appointment of Sam Clovis Jr., President Donald Trump’s nominee for a top scientific post at the Department of Agriculture, potentially dovetailing with unrelated reservations already expressed by a key Senate Republican.

Senate Minority Leader Charles E. Schumer of New York and Sen. Brian Schatz of Hawaii cited Clovis’ rejection of climate science and his “extremist views” on race and homosexuality in a press release. They called for the immediate withdrawal of his nomination as USDA undersecretary for research, education and economics.

“For Donald Trump to nominate and to advocate for Senate confirmation of someone with views as backwards as Mr. Clovis’s, is not only a signal to the darkest and most evil forces in this country to carry on, but a clear as day message to the world that this administration continues to tolerate hate,” the Democrats said in a news release.

That opposition comes weeks after Senate Agriculture Chairman Pat Roberts said he was concerned about Clovis’ 2013 suggestion that federal subsidies for crop insurance may be unconstitutional. But the Kansas Republican said at the time that he was not prepared to support the withdrawal of Clovis’ nomination.

“I don’t think we have come to that point,” Roberts said at a July committee hearing, adding that Clovis should have an opportunity to explain “why in the hell he said that.”

Sen. Debbie Stabenow, the Agriculture Committee’s ranking member, said in a statement Wednesday that if Trump does not withdraw the nomination, she would work as a panel leader “to bring to light this nominee’s troubling record and ask tough questions about his suitability for this important job.”

“From day one, I have voiced strong concerns over Sam Clovis’s lack of qualifications and extreme views,” the Michigan Democrat said.

The extent of the threat to Clovis’ nomination was not immediately clear Wednesday.

Aides for Roberts and Stabenow on the Agriculture Committee did not respond to requests for comment.

Sen. Charles E. Grassley, a Republican whose home state of Iowa is the nation’s largest corn producer, said he was confident that Clovis would do well in the job.

“I’ve known Dr. Sam Clovis for many years,” Grassley said in an emailed response through an aide. “I have confidence that with his military and educational background and knowledge of agriculture policy, Dr. Clovis will serve the country and USDA well as undersecretary for research, education and economics.”

The rumblings from both sides of the aisle stand in stark contrast to the April confirmation of Agriculture Secretary Sonny Perdue, a former Georgia governor who had broad support in the Senate and from agricultural interest groups.

Clovis, a former economics professor, conservative talk radio host and 2016 Iowa Senate candidate, has drawn criticism since his July nomination for his lack of scientific background. Opposition has mounted as journalists have uncovered scores of controversial statements he has made about race, homosexuality and climate science.

Clovis frequently argued against LGBT legal protections on radio broadcasts that aired between 2012 and 2014, CNN reported this week. He said that “LGBT behavior is a choice,” and that the sanctioning of same-sex marriage could lead to legalized pedophilia. He said on his show and in blog posts that President Barack Obama had been “given a pass” because he is black. He also called former Attorney General Eric H. Holder Jr. “a racist bigot,” and Democratic National Committee Chairman Tom Perez a “racist Latino.”

Those statements were chronicled in Schumer and Schatz’s press release.

Congress in 2008 stipulated that the USDA’s chief scientist must be drawn “from among distinguished scientists with specialized training or significant experience in agricultural research, education, and economics.” Clovis does not meet all of those criteria.

“It is clear that Clovis is unqualified from a scientific standpoint,” said Mike Lavender, a senior Washington representative for the Union of Concerned Scientists’ food and environment program. He said it should not be a tough decision for lawmakers from both parties to unanimously reject Clovis.

But Lavender acknowledged it is difficult to predict how the nomination could go and whether the White House could respond to Schumer and Schatz’s request.

Clovis, a Trump campaign adviser on agriculture, has served for several months as a key transition leader at the Agriculture Department.

While seeking the Iowa Republican nomination for the U.S. Senate in 2013, he told a talk radio show that he could not find a constitutional justification for federal subsidies for crop insurance.

That position would put him at odds with farmers and many of the lawmakers who represent them, but it is in line with policies put forth by the Trump administration. Trump proposed a 36 percent cut to the federally subsidized crop insurance program in May. Crop insurance is the largest of the USDA’s farm support programs and costs about $8 billion a year, according to Successful Farming magazine.

Clovis has since called crop insurance an important tool for farmers.