On Thursday, March 5, 2026, President Trump announced that he is firing Kristi Noem from her position as Secretary of the U.S. Department of Homeland Security, effective March 31. In her place, he plans to appoint Senator Markwayne Mullin.
Why was Kristi Noem fired, and what is the legacy she leaves behind? Who is Senator Mullin? And what is the likely impact of this change on U.S. immigration policy and enforcement? In this post, we will explore these and other important questions being asked in light of this important announcement.
Who is Kristi Noem and Why Was She Fired?
Kristi Noem started as U.S. Secretary of Homeland Security in January 2025, at the start of Donald Trump’s second presidential term. Prior to being appointed, she served as the first female governor of South Dakota. Before this, she served in the U.S. House of Representatives.
Tenure and Enforcement Actions
As Secretary of Homeland Security, Noem consistently and directly supported the harsh immigration policies and enforcement promoted by President Trump and his Deputy Chief of Staff, Stephen Miller.
She oversaw the mass detention and deportation of immigrants, the termination of various programs meant to protect immigrants (including Temporary Protected Status), and the deployment of U.S. Customs and Border Protection and other federal law enforcement agents to areas throughout the United States, including Chicago, New York, Minneapolis, and Portland.
Controversy and Dismissal
Noem faced significant criticism after, under her tenure, federal law enforcement agents shot and killed two U.S. citizens in Minneapolis: Renee Good and Alex Pretti. Immediately following the killing of Pretti, Noem claimed that he committed an act of domestic terrorism – a claim that was also made by Stephen Miller and that was clearly contradicted by video evidence that had been widely viewed.
President Trump’s frustration with Noem appears to have been building for months, in part due to the events previously described. Reporting suggests that President Trump’s ultimate decision to fire Noem came as a result of her testimony in front of the Senate Judiciary Committee, where she stated that President Trump had approved of her use of over $200 million in federal funds to pay for television advertisements that featured her.
Future Role
Days after the hearing, President Trump announced that Noem would be reassigned from Secretary of Homeland Security to “Special Envoy for The Shield of the Americas,” a previously nonexistent role about which there remains little information.
Noem will continue to serve as Secretary of Homeland Security until March 31, 2026. She is the first cabinet member to be fired in President Trump’s second term.
Who Has President Trump Announced Will Replace Noem?
At the same time that President Trump announced that Kristi Noem had been fired as Secretary of Homeland Security, he also announced that she would be replaced by Senator Markwayne Mullin on March 31, 2026. It is important to note that the position requires the confirmation of the U.S. Senate, so it is not certain that Sen. Mullin will ultimately fill the position.
Markwayne Mullin has served as a Republican Senator for the state of Oklahoma since 2023. He previously served in the U.S. House of Representatives. He is a member of the Cherokee Nation and is the only current senator without a bachelor’s degree.
With respect to his views on immigration policy and enforcement, Sen. Mullin is closely aligned with Stephen Miller, whose policies were also echoed and implemented by Kristi Noem.
What does the firing of Kristi Noem mean for U.S. immigration policy and enforcement?
Unfortunately, the replacement of Kristi Noem with Sen. Markwayne Mullin likely means little change for U.S. immigration policy and enforcement. Both Noem and Mullin are closely aligned with the positions promulgated by Stephen Miller, whose policies have frequently been described as anti-immigrant and far-right.
Potential Shifts in Tactics
This being said, reporting suggests that at least part of the reason for President Trump deciding to fire Noem was his frustration with the tactics she used to pursue his immigration agenda, including raids at work sites and aggressive tactics in U.S. cities that oftentimes harmed U.S. citizens and permanent residents.
One might also wonder whether the midterm elections scheduled for later in 2026 might motivate President Trump to reconsider the more aggressive immigration policies and tactics that his administration has implemented on his watch.
Looking Ahead
Ultimately, while there is little reason to believe that Sen. Mullin’s perspective on immigration differs significantly from Noem’s, there may be reason to hope that less harmful, punitive, and draconian treatment of immigrants in the U.S. might be on the horizon.
