Former Trump White House official Stephen Miller is blasting what he says is a "thuggish" reaction by Customs and Border Protection (CBP) after the agency announced it would be launching an investigation into rogue retweets of Miller’s criticisms of President Biden’s handling of the border crisis.

"These are bullying, intimidation and repression tactics, there's no other way to say it," Miller, now the president of America First Legal, told Fox News Digital in an interview. "And that's how they're running their government. They use these thuggish intimidation tactics to shut people up."

CBP Commissioner Chris Magnus announced last week that there will be an investigation by the Office of Professional Responsibility after the CBP account for West Texas retweeted two of Miller’s tweets.

"The media’s greatest power is its ability to frame what is a dire national crisis (eg "cops are racist" summer ‘20) and what is not," Miller, a top immigration hawk, had previously tweeted. "Biden’s eradication of our border means we are no longer a Republic—he’s ended nearly 250 years of constitutional government. The media is silent."

CBP CHIEF ANNOUNCES PROBE OF OFFICIAL TWITTER ACCOUNT THAT RETWEETED CRITICISM OF BIDEN'S BORDER ‘ERADICATION’ 

Stephen Miller

In this Oct. 30, 2020 file photo, Former President Trump's White House Senior Adviser Stephen Miller follows President Trump on the South Lawn of the White House in Washington. (AP Photo/Patrick Semansky, File)

Miller’s second tweet declared that "violent criminals lay waste to our communities undisturbed while the immense power of the state is arrayed against those whose only crime is dissent...The law has been turned from a shield to protect the innocent into a sword to conquer them."

The retweets were noticed by journalists, quickly un-retweeted, and the account later shut down and archived.

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"Totally unacceptable and disappointing that any CBP Twitter account was used to [retweet] offensive, unauthorized content," Magnus tweeted. "We’ve removed the content and will deactivate the account." 

"The Office of Professional Responsibility will investigate," he said. "This must not happen again."

Miller told Fox News Digital that while he was not initially aware of the retweets, he was ultimately not surprised considering the widely reported low morale among Border Patrol agents, given the liberal immigration policies of the Biden administration.

"I wasn't surprised at all, because I can only imagine the depth of feeling, the intensity of the discontent inside this agency being ordered to violate their oath of office every single day. That's their daily life…They show up to a job having a legal and constitutional mandate, and then their commander in chief and every subordinate underneath him that is politically appointed is ordering them to do the exact opposite of what the law and Constitution requires. And that was the point I was getting at in one of the tweets."

The furor over the retweets come amid a raging border crisis that has roiled border towns and cities since shortly after Biden took office. There have been more than 2 million encounters at the southern border and approximately 200,000 encounters a month in recent months. 

Chris Magnus testifies before the Senate Finance Committee on his nomination to be the next U.S. Customs and Border Protection commissioner,

Chris Magnus testifies before the Senate Finance Committee on his nomination to be the next U.S. Customs and Border Protection commissioner, Tuesday, Oct. 19, 2021 on Capitol Hill in Washington. (Rod Lamkey/Pool via AP)

While multiple administration officials, including Homeland Security Secretary Alejandro Mayorkas and Vice President Kamala Harris have declared the border "secure," border agents have fumed at the situation -- with Mayorkas himself previously faced the wrath of agents in person.

Miller contrasted the crackdown and investigation with Democrats having lauded whistleblowers for four years during the Trump administration.

"Now you have a situation where [President Biden] effectively set the Constitution on fire, and we're now living in a post-republic," he said. "The notion of self-governing citizens bound by a shared Constitution and a common set of laws has been completely immolated. And you have border agents, in the mildest way imaginable, conveying some degree of concern over this lawless state of anarchy and instead of doing something about that lawless anarchy, you have Magnus coming in and going after the agents."

Magnus’ pledge of an investigation came hours before an interview aired in which Harris described the border as "secure" and called for an amnesty for illegal immigrants already in the country.

"I think that there is no question that we have to do what the president and I asked Congress to do, the first request we made: pass a bill to create a pathway to citizenship," Harris said on "Meet the Press," on Sunday. "The border is secure, but we also have a broken immigration system, in particular, over the last four years before we came in, and it needs to be fixed."

White House press secretary Karine Jean-Pierre this week said that the administration had "taken unprecedented action over the past year and a half to secure our border and rebuild a safer and orderly process system."

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Miller accused the administration of "running a Soviet propaganda campaign to silence all truth telling about the border" and said that agents have few avenues to push back against what he called a "mountain of lies."

"And then you talk about something as nonchalant, as a retweet of a statement, not even appending a comment to it," he said. "Going after these agents is truly outrageous."