U.S. President Donald Trump shocked Washington when he removed Kristi Noem from her position as head of the United States Department of Homeland Security and replaced her with Senator Markwayne Mullin.

Although Trump publicly praised Noem and reassigned her to a new diplomatic role tied to the “Shield of the Americas,” reports indicate the move followed months of mounting controversies, political pressure and internal frustration within the administration.

Below are the key factors that reportedly led to her dismissal.

1. Harsh criticism over immigration enforcement

Noem became the public face of the administration’s aggressive immigration crackdown, which included mass deportation raids and expanded enforcement operations. Critics accused the department of overreach and rights violations during these campaigns.

Several lawmakers from both parties questioned her leadership during congressional hearings, where she was grilled about immigration tactics and the handling of operations nationwide.

2. A disastrous congressional hearing

One immediate trigger was a tense congressional oversight hearing just days before her removal.

Lawmakers pressed Noem about controversial immigration operations, deaths linked to federal agents and questionable spending by her department. The hearing exposed divisions even among Republicans and reportedly frustrated Trump.

3. Controversy over deaths involving federal agents

Another major issue involved the killings of two U.S. citizens during law enforcement operations connected to immigration enforcement.

The incidents sparked national outrage and intense scrutiny of the department’s tactics. Critics argued that the agency under Noem had failed to provide clear explanations about what happened.

These controversies fueled calls from lawmakers demanding accountability.

4. A $220 million advertising scandal

Perhaps the most politically damaging controversy was the revelation that the Department of Homeland Security spent more than $220 million on a national advertising campaign that prominently featured Noem.

The spending raised serious questions in Congress about whether the campaign was government messaging or self-promotion. Some lawmakers accused her of using taxpayer money to boost her own profile.

Trump reportedly denied approving the campaign, further increasing tensions inside the administration.

5. Allegations of conflicts of interest

Noem also faced questions about relationships with political advisers and whether those ties influenced decisions within the department.

These allegations contributed to the perception that leadership at DHS had become politically entangled and distracted from its core responsibilities.

6. Spending controversies involving government aircraft

Reports also revealed that the department had allocated more than $300 million for private luxury jets intended for DHS use, which critics said was unnecessary and poorly justified.

The spending added to concerns about financial management within the department.

7. Bipartisan calls for her resignation

By early 2026, frustration with Noem’s leadership was no longer limited to Democrats.

Some Republicans also began questioning her ability to lead the department, while Democrats openly pushed for her resignation or impeachment.

This bipartisan pressure significantly weakened her political standing.

8. Mounting controversies during her tenure

Throughout her time in office, Noem’s leadership repeatedly drew headlines.

Her immigration operations, strong rhetoric against sanctuary cities, and high-profile enforcement raids often sparked political and legal disputes across the country.

The accumulation of controversies created constant political pressure on the administration.

Trump’s official explanation

Despite the controversies, Trump publicly framed the decision as a reassignment rather than a punishment.

He announced that Noem would become the first U.S. Special Envoy for the Shield of the Americas, a new diplomatic initiative aimed at combating drug cartels and strengthening regional security cooperation across the Western Hemisphere.

Her departure marks the first major cabinet shake-up of Trump’s second term.

What Happens Next

If confirmed by the Senate, Markwayne Mullin will take over the Department of Homeland Security and continue implementing the administration’s immigration and border policies.

Analysts say the leadership change could either stabilize the agency after months of controversy—or intensify the administration’s already aggressive immigration strategy.

FAQ

Who is Kristi Noem?

Kristi Noem is a former governor of South Dakota who served as U.S. Secretary of Homeland Security from January 2025 until March 2026.

Why was Kristi Noem fired?

She was removed after mounting criticism over immigration enforcement, controversial spending, deaths involving federal agents and a tense congressional hearing.

Who replaced Kristi Noem?

President Donald Trump nominated Senator Markwayne Mullin to take over the Department of Homeland Security.

What job will Noem do next?

She has been reassigned as Special Envoy for the Shield of the Americas, a new regional security initiative.

Did Trump say she failed?

No. Trump publicly praised her work but decided to replace her following political pressure and controversies surrounding the department.