U.S. Sen. Michael Bennet joined 26 other Senate Democrats who wrote to President Donald Trump on Monday, demanding the “immediate removal” of White House advisor Stephen Miller.

“Continuing to employ him as the senior architect of your immigration policies ensures that those policies discriminate against individuals of color to advance white nationalist ideals,” the letter reads. “When someone takes an oath to work in the White House and earns a taxpayer-funded salary, they work for the people, not to advance a divisive, harmful and hateful ideology.”

The letter referred to more than 900 e-mails of Miller’s that the Southern Poverty Law Center recently obtained. In that correspondence, SPLC found Miller aligned with tenets of far-right nationalism.

Senators also named the policies the White House has advanced with Miller’s involvement, including the Muslim ban, the end of the Deferred Action for Childhood Arrivals program, and the limitation of refugee admissions.

“Each and every one of these policies has a disproportionate adverse impact on communities of color and our country. Each and every one of them aligns with the white nationalist ideals espoused by Mr. Miller in his e-mails,” senators argued.

An e-mail sent to the office of U.S. Cory Gardner was not returned, asking if he had an opinion on Miller’s employment or his ideology as characterized by the Democratic senators.