Photo: ERIN SCHAFF, STF / NYT

WASHINGTON — A prominent Texas Democrat is joining calls from Congress for the resignation of a White House adviser credited with shaping President Donald Trump’s immigration policies after the Southern Poverty Law Center published emails showing the adviser promoting white nationalist viewpoints.

U.S. Rep. Joaquin Castro, a San Antonio Democrat who leads the Congressional Hispanic Caucus, on Thursday called Stephen Miller “a white nationalist” who “has no business serving in the White House.”

“It’s clearer than ever that Stephen Miller is a far-right white nationalist with a racist and xenophobic worldview,” Castro said in a statement issued with the leaders of the Congressional Black Caucus, Congressional Asian Pacific American Caucus and the Congressional Progressive Caucus. “His beliefs are appalling, indefensible, and completely at odds with public service.”

The statement follows the Southern Poverty Law Centers’ publication of emails Miller sent before joining the White House to a then-editor at conservative news outlet Breitbart, pushing what the legal advocacy group called “white nationalist literature” and “racist immigration stories.” The emails contained links from websites including the conspiracy site InfoWars and VDARE, which regularly publishes white nationalists and is a hub for anti-immigrant messaging.

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The emails were sent in the runup to the 2016 election, when Miller was an aide to then-Sen. Jeff Sessions, who later served as Trump’s attorney general. They were sent to Katie McHugh, a former Breitbart editor fired after posting anti-Muslim tweets in 2017. McHugh has since renounced the far right and provided the emails to the Southern Poverty Law Center.

Among them was an October exchange in which McHugh wrote to Miller asking whether Hurricane Patricia would drive refugees to the U.S.

“This being the worst hurricane ever recorded, what are the chances it wreaks destruction on Mexico and drives a mass migration to the U.S. border?” she wrote.

“100 percent,” he responded. “And they will all get TPS. And all the ones here will get TPS too. That needs to be the weekend's BIG story. TPS is everything.”

Miller was referring to Temporary Protected Status, granted to those in the U.S. from war-torn countries and those devastated by natural disasters. In a subsequent email, Miller shared a link to a VDARE article by an author the Southern Poverty Law Center says “traffics in discredited race science.”

“As documented by the Southern Poverty Law Center, Stephen Miller has embedded himself in white nationalist doctrine for years, including promoting racist propaganda from fringe sites like VDARE and InfoWars,” Castro and the other Democrats said. “And as the chief architect of the Muslim Ban and cruel family separation policies, Stephen Miller has spent the last three years turning his bigotry into policy — with President Trump’s blessing.”

White House Principal Deputy Press Secretary Hogan Gidley said in a statement that “the SPLC libels, slanders and defames conservatives for a living and in fact, is a discredited, debunked far-left smear organization.”

“I work with Stephen. I know Stephen,” Gidley said. “He loves this country and hates bigotry in all forms - and it deeply concerns me as to why so many on the left consistently attack Jewish members of this administration.”

ben.wermund@chron.com