Sam Clovis on Thursday withdrew his nomination to serve as the U.S. Agriculture Department’s chief scientist.

Clovis withdrew his nomination days after unsealed court documents revealed that his communications with other members of President Donald Trump’s campaign put him in proximity to the federal investigation into Russian interference in the 2016 election.

In a letter to Trump dated Wednesday, Clovis claimed, “The political climate inside Washington has made it impossible for me to receive a balanced and fair consideration for this position.”

Clovis said he did not want to “be a distraction or negative influence.”

“I worked hard during the campaign and take some pride in the accomplishment of having you elevated to the Presidency,” Clovis wrote.

Sam Clovis’s letter withdrawing from consideration for undersecretary post at US Agriculture Dept. pic.twitter.com/Rawsd1727y — Jennifer Jacobs (@JenniferJJacobs) November 2, 2017

“We respect Mr. Clovis’ decision to withdraw his nomination,” White House press secretary Sarah Huckabee Sanders said in a statement.

Ironically, it was precisely the “hard” work Clovis claimed he did on Trump’s behalf during his 2016 campaign that put Clovis’ nomination in question to begin with.

Clovis served as the supervisor to George Papadopoulos, a former adviser on Trump’s campaign. Papadopoulos pleaded guilty earlier in October to lying to the FBI about his contacts with Russian nationals.

According to court documents unsealed on Monday, Papadopoulos kept other members of Trump’s campaign updated on those communications. In several messages, Clovis told Papadopoulos he’d done “great work” with his initial outreach to Russians who wanted to set up a meeting, and Clovis said he “would encourage” Papadopoulos to set one up “off the record.”

NBC News reported Tuesday that special counsel Robert Mueller’s team questioned Clovis, and that Clovis testified before the investigating grand jury in the Russia probe.

White House press secretary Sarah Huckabee Sanders on Tuesday said she was “not aware of any change that would be necessary” with regard to Clovis’ nomination.

Sen. Chuck Grassley (R-IA) on Wednesday said that Clovis’ scheduled testimony before the Senate Agriculture Committee, scheduled for next Thursday, could be pushed back. Grassley said it was “too early” to say whether he thought Clovis would face legal consequences, but said he is nevertheless still backing Clovis’ nomination.

CNN first reported on Thursday morning, citing an unnamed White House source, that Clovis’ nomination could be yanked.

Clovis, Trump’s pick to oversee the Department of Agriculture’s research section, is a non-scientist and open climate skeptic.

Senate Minority Leader Chuck Schumer (D-NY) and Sen. Brian Schatz (D-HI) in August cited Clovis’ “backwards” views in a statement calling on Trump to withdraw Clovis’ nomination.

“He is a proud ‘skeptic’ of climate change and wildly unqualified for the position of USDA Chief Scientist,” the senators said.

The Washington Post reported on Thursday, citing a letter from Clovis to Sen. Debbie Stabenow (D-MI), the top Democrat on the Senate Agriculture, Nutrition and Forestry Committee, that Clovis repeatedly responded to questions about what science credentials he has as “None.”

Clovis instead cited his teaching career (focused on homeland security, foreign policy and political science) and his experience running for office as proof that he is qualified to be the department’s top scientist.

This post has been updated.