Washington (CNN) Stephen Miller, the controversial senior White House policy adviser with hardline immigration views, coordinated with editors at far-right news site Breitbart to shape its immigration coverage, pushing criticism of Republican Sen. Marco Rubio's immigration policies, and otherwise directing editorial coverage, newly released emails from 2015 show.

The emails were released Tuesday by the Southern Poverty Law Center, after they were leaked to the organization by a former Breitbart editor, Katie McHugh. McHugh was fired in 2017 after anti-Muslim remarks following a terrorist attack in London.

In the years since her time at Breitbart, McHugh has renounced her views and worked to expose members of the far right.

Neither Miller nor the White House responded to a CNN request for comment about the latest batch of emails. Rubio's office also did not respond to a CNN request for comment.

Elizabeth Moore, a Breitbart spokesperson, told CNN: "It is no surprise to us that the SPLC opposes news coverage of illegal-immigrant crime and believes such coverage is disproportionate, especially when compared to the rest of the media, which often refuse to cover such crimes."

The emails show that Miller, an aide to then-Alabama Republican Sen. Jeff Sessions at the time, often made editorial suggestions to Breitbart staff. On more than one occasion, the website's staff aggregated stories at Miller's suggestion and placed certain stories prominently on their website when Miller emailed them about it.

Breitbart also ran a press release authored by Miller under the byline "Breitbart News", which Miller suggested.

"I think Breitbart News (should be the byline,)" Miller told Breitbart editor Matthew Boyle. "Then it can be introduced as something shared exclusively with Breitbart by the Senate's Subcomittee (sic) on Immigration and the National Interest, with the graphic and explanatory text underneath."

Others copied to the email include Steve Bannon, who was leading the far-right website at the time, Sessions aide Garrett Murch, McHugh and three other Breitbart employees.

The press release ended up in a story entitled: "Exclusive -- Senate Immigration Subcommittee Releases Chart Proving Immigration Will Outpace American Population Growth 7 To 1 Through 2065," under the byline "Breitbart News."

In another email, Miller said the publication should aggregate a piece written by a conservative pundit criticizing Rubio's presidential run. An article on the subject was was posted to Breitbart's website hours later.

"My editors were expecting me to take white nationalist material from Stephen Miller and put it into News stories in order to boost the campaign of Donald Trump," McHugh told CNN in a phone interview.

On at least 10 occasions, Miller pushed the website's staff to criticize then-presidential candidate Marco Rubio's immigration policy stance, according to the Southern Poverty Law Center report released Tuesday

"Been a long time since anything anti-rubio was pub'd," Miller wrote in an April 2015 email, according the center's report

Two months later, Miller sent along a Roll Call story entitled : "Can Marco Rubio Save the GOP in 2016?" It mentioned Rubio's Cuban heritage and the diversity of the Republican pool of presidential candidates.

"this is how it begins," Miller's email subject line said.

In December 2015, he wrote: "The only difference between Jeb [Bush] and Rubio is Jeb is honest and Rubio is pathological[.]"

McHugh said she believes Miller's anti-Rubio position was "from a place of racial animus."

"Stephen Miller appeared to have a very specific vendetta against Marco Rubio. He would always call him an extremist where it was Miller who was extremist," she said.

"Miller was trying to orchestrate the idea (of) this narrative that not only people of color or people who are Muslims dangerous individuals but they are an existential threat to the country that is what he was trying to push," she added.

Michael Edison Hayden, an employee for the Southern Poverty Law Center reviewed the emails leaked by McHugh, also said that Miller's emails about Rubio were sometimes racially motivated.

"With Marco Rubio, (Miller) made what I would describe as heavily racially motivated attacks. There is, for example, one email, in which he sends with the subject line 'this is how it begins.' The email features an article which is about how diverse the field of the GOP nomination is, noting that Rubio is a Cuban American," Hayden told CNN.

In another segment of the emails, Miller credits the far-right website with the demise of a so-called Gang of Eight immigration bill co-sponsored by Rubio.

"If not for Breitbart, the bill would have become law," Miller wrote in an email which included Breitbart editor Boyle and Bannon.

The White House defended Miller following the release of the first set of emails and claimed that the Southern Poverty Law Center has been waging an anti-Semitic attack against him. However, they have not addressed or defended the specific actions Miller took with Breitbart employees.

"SPLC is engaged in a vile smear campaign against a Jewish staffer. While Mr. Miller condemns racism and bigotry in all forms, those defaming him are trying to deny his Jewish identity which is a pernicious form of anti-Semitism," a White House official said in a statement to CNN.

Hayden said that he'd reached out to Miller for comment nearly a month ago.

He knew what was coming and he had time to prepare for it and this was all he could come up with because he knows the emails are his.

"Emails are emails," Hayden said. "Southern Poverty Law Center fights tirelessly against all hate, including anti-Semitism."

This story has been updated with a new statement from Breitbart.