Here are the facts.
President Donald Trump announced Wednesday that he is replacing Department of Homeland Security Secretary Kristi Noem, marking one of the most significant leadership changes in his administration’s second term.
Noem, the former South Dakota governor who has overseen the Department of Homeland Security during a period of aggressive immigration enforcement and border security operations, will move into a new role within the administration.
In a statement posted on Truth Social, Trump revealed that he plans to nominate Oklahoma Sen. Markwayne Mullin to become the next Secretary of Homeland Security beginning March 31.
Trump thanked Noem for her work and highlighted what he described as major successes during her time leading DHS.
“The current Secretary, Kristi Noem, has served our administration well and achieved major successes, particularly when it comes to securing the border,” Trump wrote. “She will now transition into a new position as Special Envoy for the ‘Shield of the Americas.’”
The president said the new initiative will focus on strengthening security cooperation across the Western Hemisphere and will be formally announced during an event in Doral, Florida later this week.
Trump Nominates Markwayne Mullin to Lead DHS
Trump said Sen. Markwayne Mullin is well qualified to take over leadership of the Department of Homeland Security and continue the administration’s focus on border enforcement and national security.
The Oklahoma Republican previously served in the House of Representatives before winning election to the Senate. Before entering politics, Mullin worked in the private sector and also built a reputation as an undefeated mixed martial arts fighter.
Trump praised Mullin’s leadership and commitment to protecting American communities.
“Markwayne has done a tremendous job in Congress,” Trump wrote. “He will work tirelessly to secure our border, stop migrant crime, combat illegal drug trafficking, and keep American families safe.”
Mullin is also currently the only Native American serving in the United States Senate, following the tenure of former Colorado Sen. Ben Nighthorse Campbell decades earlier.
Temporary Leadership At Homeland Security
Until Mullin is confirmed by the Senate, DHS Deputy Secretary Troy Edgar is expected to oversee day-to-day operations at the department.
Edgar, a Navy veteran and former mayor of Los Alamitos, California, sits next in the chain of command at the Department of Homeland Security.
The agency plays a central role in enforcing immigration laws, managing border security, coordinating federal disaster response, and protecting the United States from security threats.
Noem’s Record On Border Security
During her time leading DHS, Noem oversaw a major shift in immigration enforcement compared to policies under the previous administration.
Officials say the department recorded significant increases in drug seizures at the southern border, intercepting more than half a million pounds of illegal narcotics in her first year.
Supporters of the administration also point to the results of President Trump’s mass deportation initiative.
Government figures indicate roughly 670,000 illegal immigrants were removed from the United States in 2025, while more than 2 million individuals reportedly chose to leave the country voluntarily amid stepped-up enforcement efforts.
Backers of the administration have described the operation as one of the most extensive immigration enforcement efforts in modern U.S. history.
Political Tensions Surround Immigration Enforcement
Noem’s aggressive approach to immigration policy frequently brought her into conflict with Democratic leaders and immigration activists.
Several Democratic officials, including California Gov. Gavin Newsom and members of Congress, criticized federal immigration operations and accused DHS of heavy-handed tactics.
In one high-profile dispute, Maryland political figure David Trone accused federal agents of misconduct during a protest outside a planned immigration detention facility. DHS officials strongly rejected the accusations.
The immigration debate also intensified in Minneapolis, where enforcement operations sparked political controversy and eventually led to leadership changes within the regional Border Patrol command.
Heated Congressional Hearing
Noem faced tough questioning this week during hearings before congressional committees, where Democratic lawmakers challenged the department’s policies and raised various allegations.
One exchange became particularly tense when Rep. Sydney Kamlager-Dove of California asked Noem about rumors involving Corey Lewandowski, a former Trump campaign adviser who has worked with the department in a special government role.
Noem sharply criticized the line of questioning and called the allegations inappropriate.
She told lawmakers that such accusations were politically motivated and unfair.
Republicans on the committee also accused Democrats of attempting to distract from the department’s national security responsibilities.
Republicans Praise Noem’s Leadership
Several Republican lawmakers defended Noem during the hearings and praised her leadership at DHS.
Rep. Clay Higgins of Louisiana, a former law enforcement officer, said Noem helped reverse years of what Republicans viewed as ineffective immigration policies.
“You inherited a disaster and turned it around,” Higgins said. “A 97 percent drop in illegal crossings doesn’t happen by accident. That’s leadership.”
Supporters argue that the administration’s policies have restored stronger border security and reinforced immigration enforcement nationwide.
What Comes Next
Although Noem is leaving her role at DHS, the White House emphasized that she will remain a key part of the administration’s national security strategy.
As Special Envoy for the “Shield of the Americas” initiative, she is expected to focus on regional security cooperation, cross-border crime prevention, and strengthening partnerships with nations across the Western Hemisphere.
The program will be formally unveiled during the president’s upcoming announcement in Florida.
Meanwhile, the nomination of Sen. Markwayne Mullin to lead the Department of Homeland Security will now move to the Senate confirmation process — setting the stage for another major development in President Trump’s ongoing effort to reshape U.S. immigration and border security policy.