CNN’s Jim Acosta finally got to ask a question at a White House press briefing. Unfortunately for him, it was Trump adviser Stephen Miller who answered it.

Press Secretary Sarah Huckabee Sanders trotted out Miller on Wednesday to help sell the administration’s new skills-based immigration plan (which Miller had helped craft) and it did not take long for the combative senior Trump aide to start going at it with reporters like NBC News’ Hallie Jackson and The New York Times’ Glenn Thrush.

But he saved the best for last when he called on Acosta to ask a final question about a policy that would aim to “limit family-based migration” and force prospective green card recipients to learn English before arriving in the United States.

“What the pre sident's proposing here does not sound like it's in keeping with American tradition when it comes to immigration,” Acosta began, seizing his moment. “The Statue of Liberty says, ‘Give me your tired, your poor, your huddled masses, yearning to breathe free.’ It doesn't say anything about speaking English or being able to be a computer programmer. Aren't you trying to change what it means to be an immigrant coming into this country if you're telling them, you have to speak English? Can’t people learn how to speak English when they get here?”

Miller pushed back on Acosta’s assertion, arguing that it is “ahistorical” to suggest that immigrants do not need to learn how to speak English. As he attempted to dispute the origins of the poem on the Statue of Liberty, Acosta interrupted him.

“You're saying that does not represent what the country has always thought of as generations coming into this country. Stephen, I’m sorry, that sounds like some national park revisionism,” the CNN reporter said. “The Statue of Liberty has always been a beacon of hope to the world for people to send their people to this country. They're not always going to speak English, Stephen. They're not always going to be highly skilled.”

This caused Miller, who had been relatively calm throughout the press conference, to officially lose his cool.

“Tell me what years meet Jim Acosta's definition of the Statue of Liberty poem law of the land. So you're saying a million a year is the Statue of Liberty number?” he asked.

“You're sort of bringing a press one for English philosophy here to immigration and that's never been what the united states has been about, Stephen,” Acosta shot back. He went on to inform Miller that he own father came to this country as a Cuban immigrant in the 1960s and obtained a green card. “Are we just going to bring in people from Great Britain and Australia?” he asked.

“I have to say, I am shocked at your statement that you think that only people from Great Britain and Australia would know English,” Miller replied. “It reveals your cosmopolitan bias to a shocking degree.”

Acosta held firm, telling Miller, “It j ust sounds like you're trying to engineer the racial and ethnic flow of people into this country.”

“That is one of the most outrageous, insulting, ignorant, and foolish things you’ve ever said,” an incensed Miller shot back. “The notion that you think that this is a racist bill is so wrong and so insulting.” In reality, Miller called the bill “racist” before Acosta did.

Miller has been one of Trump’s most influential advisers on hardline immigration policy, and this dates back to before Miller even joined the 2016 presidential campaign. As The Daily Beast reported last month, he was the principal author behind the Trump campaign’s immigration-policy “white paper” released in August 2015. (Miller officially joined Team Trump in January 2016.)

In the Trump White House, Miller—who has long agitated against legal, not just illegal, immigration—was a primary driver behind the “Muslim ban,” along with chief strategist Steve Bannon, another prominent nationalist and anti-immigration voice in Trump’s inner circle. Miller currently serves as a top speechwriter for President Trump.

"Well, you can be Cuban and cosmopolitan," Acosta told CNN's Brooke Baldwin, with a laugh, following the briefing. "I think when the White House has to resort to insulting reporters in that fashion — and we've seen this time and again throughout the course of this administration — they're just really not advancing a terribly powerful argument." He later added that Trump's "bias against Latino immigrants has just sort of infected" both the president and his top officials, "and I think you saw some of that spill out in the briefing room today."

Miller’s heated exchange with Acosta on Wednesday afternoon is pure Stephen Miller. As a former Jeff Sessions aide and longtime ideological firebrand, Miller has been known in Washington, DC, political and media circles for years as someone who relishes having long arguments and conversations about immigration policy and data, and why the U.S. system should be decidedly more restrictive.

“[Stephen] had a blast,” a senior White House official told The Daily Beast after the briefing wrapped. “This is his fight.”