Amicus Curiae Brief — Donald J. Trump, President of the United States, et al., Applicants v. Illinois, et al.

No. 25A443

IN THE

Supreme Court of the United States

DONALD J. TRUMP, PRESIDENT OF THE UNITED STATES, ET AL.,

Applicants,

v.

STATE OF ILLINOIS AND CITY OF CHICAGO,

Respondents.

On Application to Stay the Order Issued by the United

States District Court for the Northern District of Illinois

and Request for an Immediate Administrative Stay

BRIEF OF THE STATES OF IOWA, MONTANA, OKLAHOMA, SOUTH CAROLINA

AND 18 ADDITIONAL STATES AS AMICI CURIAE IN SUPPORT

OF APPLICATION FOR STAY

BRENNA BIRD

Attorney General of Iowa

ERIC H. WESSAN

Solicitor General

1305 E. Walnut Street

Des Moines, Iowa 50319

(515) 823-9117

(515)281-4209 (fax)

eric.wessan@ag.iowa.gov

Counsel for the State of Iowa

AUSTIN KNUDSEN

Attorney General of Montana

CHRISTIAN B. CORRIGAN

Solicitor General

Counsel of Record

MONTANA DEPARTMENT

OF JUSTICE

215 N Sanders

Helena, MT 59602

(406) 444-2026

christian.corrigan@mt.gov

Counsel for the State of Montana

Additional counsel

signature block

listed

on

i

TABLE OF CONTENTS

TABLE OF CONTENTS ................................................................................................... i

TABLE OF AUTHORITIES ............................................................................................ ii

INTERESTS OF AMICI CURIAE .................................................................................. 1

ARGUMENT .................................................................................................................... 2

I.

Violent rioters in Chicago are harming federal officers and property and

impacting the Federal Government’s ability to carry out Federal laws. ............ 2

II.

President Trump certainly has a “colorable basis” for federalizing the National

Guard to protect federal agents and property from violent rioters in Chicago. . 5

III.

The harms incurred if violent and destructive protests and riots are allowed to

continue in Chicago are borne by all states. ........................................................ 7

CONCLUSION............................................................................................................... 10

ii

TABLE OF AUTHORITIES

Cases

Arizona v. United States, 567 U.S. 387 (2012) ............................................................................ 8

Blackie’s House of Beef, Inc. v. Castillo, 659 F.2d. 1211 (D.C. Cir. 1981) ................................. 10

California v. United States, 104 F.3d 1086 (9th Cir. 1997)......................................................... 7

Newsom v. Trump, 141 F.4th 1032 (9th Cir. 2025) ................................................................. 5, 6

Sterling v. Constantin, 287 U.S. 378 (1932) ................................................................................ 6

United States v. Texas, 599 U.S. 670 (2023) ............................................................................ 7, 8

Statutes

10 U.S.C. § 12406 ..................................................................................................................5, 6, 7

10 U.S.C. § 251 ............................................................................................................................. 7

18 U.S.C. § 1385 ........................................................................................................................... 7

Other Authorities

Audrey Conklin, California sheriff says Newsom ‘encouraged’ LA riots as ICE arrests violent

illegal aliens, Fox News (Jun. 10, 2025)................................................................................... 2

Chris Nesi, Chicago police ordered to ignore Border Patrol agents’ plea for help while

surrounded by angry mob of protesters, N.Y. Post (Oct. 5, 2025_........................................ 2, 3

Chris Nesi, House Judiciary Committee opens probe into taxpayer-funded group’s potential

ties to LA anti-ICE riots, N.Y. Post (June 24, 2025) ................................................................ 8

Connor Greene & Brian Bennett, ‘Push Back Against Tyranny’: Chicago and Illinois Fight

Trump’s Intensifying Crackdown, Time (Oct. 6, 2025) ............................................................ 4

DHS Issues Statement on Targeted Attack on Dallas ICE Facility, DHS (Sept. 24, 2025) ........ 9

Holly Yan & Priscilla Alvarez, A 2nd detainee — a father of 4 — dies after a gunman opened

fire at an ICE office in Dallas, CNN (Sept. 30, 2025) ............................................................ 10

Jennifer A. Kingson, Exclusive: $1 billion-plus riot damage is most expensive in insurance

history and rioters, AXIOS (Sept. 16, 2020) ............................................................................. 8

John O’Connor, Noem visits Chicago area ICE facility as agents arrest 13, raid city

neighborhoods, AP (Oct. 3, 2025) ............................................................................................. 3

Molly Parks, Pritzker vows to boot Noem’s ICE ‘thugs’ from Chicago, Washington Examiner

(Oct. 6, 2025) ............................................................................................................................. 4

Natasha Korecki & Daniella Silva, Illinois officials issue orders and file lawsuits as protesters

clash with immigration agents, NBC News (Oct. 6, 2025) ...................................................... 3

Sophia Tareen, Chicago area center in Trump’s immigration crackdown sparks complaints of

inhumane conditions, AP (Sept. 25, 2025) ............................................................................... 4

Trevor Hughes, Protests in Minneapolis turned violent: Officials first blamed outsiders, but

that’s not what arrests show, USA Today (updated June 4, 2020) .......................................... 9

iii

Violent Rioters Assault Law Enforcement at ICE Broadview Processing Center, Police under

JB Pritzker’s Sanctuary Jurisdiction Refuse to Answer Calls to Help Stop Assaults, DHS

(Sept. 19, 2025) ..................................................................................................................... 3, 5

Will Hager, Chicago establishes ICE-free zones: Here’s what we know, FOX 32 (Oct. 6, 2025) . 4

Regulations

Designating Antifa as a Domestic Terrorist Organization, 90 Fed Reg. 46317, 46317 (Sept. 22,

2025).......................................................................................................................................... 9

Constitutional Provisions

U.S. Const. art. I, § 8, cl. 15 ......................................................................................................... 6

1

INTERESTS OF AMICI CURIAE

For the past four years, illegal open-border immigration policies flooded the

country with illegal aliens, including criminals convicted of crimes in their home

country, violent international gang members, and suspected ISIS terrorists. Much of

that was done in violation of federal immigration law through the assertion of executive

enforcement prerogatives. Now, President Trump is executing Congress’s dictates and

enforcing federal immigration law—which includes valiant efforts by federal law

enforcement to identify and deport alien criminals. Against that backdrop of law

enforcement, activists began to gather in cities across the United States, including

Chicago. But rather than protest peacefully, some of the protestors became violent,

threatening federal officers, harming federal property, and certainly impeding

enforcement of federal law. President Trump’s deployment of a small number of

National Guard members to defend against this lawlessness is responsible,

constitutional, and authorized by statute.

Amici Curiae are the States and Commonwealths of Iowa, Montana, Oklahoma,

South Carolina, Alabama, Alaska, Arkansas, Florida, Georgia, Idaho, Indiana, Kansas,

Kentucky, Louisiana, Mississippi, Missouri, Nebraska, North Dakota, Ohio, South

Dakota, Texas, and West Virginia, which submit this brief in support of Defendants.

Prohibiting the deployment of the National Guard to ensure ICE agents are able to

fulfil their duties safely and effectively comes at an immense cost to the States. The

undersigned States recognize the important roles and balance played in the National

Guard system by both the States and federal government. But Plaintiffs fail to respect

that balance here.

2

ARGUMENT

I.

Violent rioters in Chicago are harming federal officers and

property and impacting the Federal Government’s ability to

carry out Federal laws.

Recently, violence against federal immigration officials has increased. “The men

and women of ICE put their lives on the line to protect and defend the lives of American

citizens,” ICE Assistant Secretary Tricia McLaughlin recently said in a statement.

Audrey Conklin, California sheriff says Newsom ‘encouraged’ LA riots as ICE arrests

violent illegal aliens, Fox News (Jun. 10, 2025), https://tinyurl.com/y942z342.

McLaughlin also noted that “[d]emocrat politicians … are contributing to the surge in

assaults of our ICE officers through their repeated vilification and demonization of

ICE,” referencing comparisons made “to the modern-day Nazi gestapo” and to

“glorifying rioters.” Id. Indeed, there are real-world consequences to Chicago’s poor

treatment of federal immigration officials and inaction to address violence against

them.

In September 2025, violence toward ICE agents in Chicago began to escalate

after ICE began “Operation Midway Blitz”—an initiative to “target the criminal illegal

aliens who flocked to Chicago and Illinois because they knew Governor [JB] Pritzker

and his sanctuary policies would protect them and allow them to roam free on American

streets.” Chris Nesi, Chicago police ordered to ignore Border Patrol agents’ plea for help

while surrounded by angry mob of protesters, N.Y. Post (Oct. 5, 2025, at 6:51 pm),

https://nypost.com/2025/10/05/us-news/chicago-police-ordered-to-ignore-border-patrolagents-plea-for-help-while-surrounded-by-angry-mob-of-protesters/. The Broadview

Processing Center in Chicago “continues to face violence and unlawful activity by

rioters.” Natasha Korecki & Daniella Silva, Illinois officials issue orders and file

3

lawsuits as protesters clash with immigration agents, NBC News (Oct. 6, 2025, at 1:34

pm),

https://www.nbcnews.com/news/us-news/broadview-mayor-limits-hours-

protestors-ice-facility-escalating-clashe-rcna235957.

More than one hundred people have surrounded the Center and “assaulted law

enforcement, threw tear gas cans, slashed tires of cars, blocked the entrance of the

building, and trespassed on private property.” Violent Rioters Assault Law Enforcement

at ICE Broadview Processing Center, Police under JB Pritzker’s Sanctuary Jurisdiction

Refuse

to

Answer

Calls

to

Help

Stop

Assaults,

DHS

(Sept.

19,

2025),

https://bit.ly/3IP2Rvi. So far, these riots have resulted in federal agents having to arrest

at least 13 people. Christine Fernando & John O’Connor, Noem visits Chicago area ICE

facility as agents arrest 13, raid city neighborhoods, AP (Oct. 3, 2025, at 5:26 pm),

https://bit.ly/4q53mSM.

But the threat ICE agents face in Chicago is not limited to the Broadview Center.

ICE agents, who were on patrol about 15 miles from the Broadview facility, “were

attacked and rammed by vehicles and boxed in by 10 cars.” Nesi, supra. ICE agents

“attempted to flee their trapped vehicle,” but a woman, carrying a semi-automatic

weapon, “attempted to run the officers down.” Id. Astonishingly, local police, who were

initially prepared to help ICE, were told to “stand down by the chief of patrol.” Id.

Despite the continued violence occurring at the ICE facility and toward ICE in

general, Chicago Mayor Brandon Johnson has continuously decried any federal help

and has gone so far as to sign an executive order declaring “‘ICE-free zones’ throughout

the city to limit the areas where federal authorities can operate.” Connor Greene &

Brian Bennett, ‘Push Back Against Tyranny’: Chicago and Illinois Fight Trump’s

4

Intensifying Crackdown, Time (Oct. 6, 2025, at 4:26 pm), https://bit.ly/4nIPZ98. He has

done so in a purported effort to “check” the administration, “build[] a broader civic

shield that limits the reach of harmful enforcement practices” and “reaffirms Chicago’s

role as a welcoming city.” Will Hager, Chicago establishes ICE-free zones: Here’s what

we know, FOX 32 (Oct. 6, 2025, at 10:17 am), https://bit.ly/4nyCvwy. Illinois Governor

JB Pritzker has similarly demanded federal officers “stay the hell out of Chicago,” Molly

Parks, Pritzker vows to boot Noem’s ICE ‘thugs’ from Chicago, Washington Examiner

(Oct. 6, 2025, at 5:44 pm), https://bit.ly/46Yyf2n, and called the President’s attempt to

protect ICE by deploying the National Guard an “unconstitutional invasion.” Greene &

Bennett, supra.

Even before the current conflict, Illinois has enforced some of “the nation’s

strictest sanctuary laws, widely barring cooperation between local police and federal

immigration agents, including for detention.” Sophia Tareen, Chicago area center in

Trump’s immigration crackdown sparks complaints of inhumane conditions, AP (Sept.

25, 2025, at 4:04 pm), https://bit.ly/439Fp2x. “The state effectively banned immigration

detention in 2021, when it ended local cooperation agreements between the federal

government and county jails. Illinois barred private detention in 2019 following failed

attempts to build a new detention facility and there are no federal immigration

detention centers in the state.” Id.

Given the prevalence of violence aimed at federal law enforcement, in Chicago

and around the country, it is unsurprising that the President deployed National Guard

resources to protect them from obstructions in their attempts to follow the law.

5

II.

President Trump certainly has a “colorable basis” for

federalizing the National Guard to protect federal agents and

property from violent rioters in Chicago.

Federal law explains that “[w]henever … the President is unable with the regular

forces to execute the laws of the United States … the President may call into Federal

service members and units of the National Guard of any State in such numbers as he

considers necessary to … execute those laws.” 10 U.S.C. § 12406(3). In Newsom v.

Trump, 141 F.4th 1032, 1052 (9th Cir. 2025), a panel of the Ninth Circuit correctly held

that the President indeed had “a colorable basis for invoking” section 12406(3) to

federalize the National Guard in Los Angeles. The panel used “a highly deferential

standard of review” to determine if there was a “colorable assessment of the facts and

law within a ‘range of honest judgment’” to warrant such a decision. Id. at 1051-52. In

determining that the President’s actions were authorized, the Court referenced that the

defendants had presented evidence “of protesters’ interference with the ability of

federal officers to execute the laws,” noting violence against federal officers, including

throwing objects, ramming gates, and vandalizing property. Id. at 1052. The court also

noted that defendants’ declarations there showed how “those activities significantly

impeded the ability of federal officers to execute the laws.” Id.

This Court should employ this same analysis, under which, there is no doubt that

the President’s decision to send national guard members to Chicago reflects a similar

“colorable assessment of the facts and law within a ‘range of honest judgment.’” Id. at

1051. There has been a continuous and growing threat outside of the ICE building in

Chicago. Hundreds of protesters have gathered, assaulted ICE agents, and actively

worked

to

block

agents

from

accessing

the

building.

See

supra,

https://www.dhs.gov/news/2025/09/19/violent-rioters-assault-law-enforcement-ice-

6

broadview-processing-center-police. And the President’s order to send approximately

300 National Guard members, contrasted with the ~4,000 deployed in California in

Newsom, shows that there is a measured response here. That is not to say that the

President cannot federalized more members, but this response certainly shows that it

was a reasoned decision based on the facts as known at the time. The President’s

response here was certainly “within a ‘range of honest judgment.’” Newsom, 141 F.4th

at 1050 (quoting Sterling v. Constantin, 287 U.S. 378, 399–400 (1932)).

Additionally, the phrase “regular forces” also does not prevent the President from

federalizing the national guard here. First, the Ninth Circuit correctly stated that the

phrase “regular forces” means not only the regular armed forces but also “federal

officers” more generally, i.e., the federal law enforcement personnel who are engaged in

executing federal immigration laws or making arrests of individuals who are violating

criminal laws, here ICE and Federal Protective Services officers. See Newsom, 141

F.4th at 1051-52. This interpretation is supported by § 12406(3)’s plain text which

refers to the “regular forces” who are engaged in “execut[ing] the law.” The statute

contains a three-part structure that mirrors the three circumstances described in

Article I, Section 8, Clause 15 of the Constitution enumerating that Congress has the

power “[t]o provide for calling forth the Militia [1] to execute the Laws of the Union, [2]

suppress Insurrections and [3] repel Invasions.” U.S. Const. art. I, § 8, cl. 15. There is

no indication in the constitutional or statutory text that “execut[ing]” the laws was

limited to the “army” or “navy.” Moreover, interpreting “regular forces” to be limited to

the regular armed forces, would make § 12406(3) of little effect because the United

States military does not regularly “execute the law,” as Congress has generally

7

forbidden them from doing so in the absence of express statutory authorization. See 18

U.S.C. § 1385. This interpretation would mean that the President must first invoke a

federal law such as the Insurrection Act, 10 U.S.C. § 251 et seq. before he could call up

the national guard to assist the “regular forces.”

Therefore, it would make little sense to provide that the national guard may be

called up only to assist the regular army and navy with executing the laws of the United

States. Instead, it makes much more sense to interpret § 12406(3) as authorizing the

President to federalize the national guard to ensure federal laws are upheld as “regular

forces,” including federal officers, such as ICE and Federal Protective Services officers

execute the laws.

III.

The harms incurred if violent and destructive protests and

riots are allowed to continue in Chicago are borne by all

States.

The President’s decision to federalize the national guard to protect federal

officers and property in Chicago has effects beyond the borders of Illinois; States and

cities across the U.S. are benefited by this decision.

States are already impacted with the immense costs of illegal immigration.

States have been required to bear numerous financial costs as a result of illegal

immigration including cost related to incarceration and supervisions of criminal illegal

aliens, the cost of criminal recidivism, and public education and healthcare costs. See

United States v. Texas, 599 U.S. 670, 716-17 (2023) (Alito, J., dissenting). These

expenses have collectively cost the States billions. See California v. United States, 104

F.3d 1086, 1090 (9th Cir. 1997). These costs are particularly acute, where the Supreme

Court has left the States without recourse to address immigration-related harms

8

outside of federal enforcement. See Arizona v. United States, 567 U.S. 387 (2012)

(holding that a state generally may not enact a law that addresses the subject of

immigration because Congress has “occupied the field.”); Texas, 599 U.S. at 674

(holding a state is precluded from suing to ensure that the federal government is

enforcing immigration laws). As the United State Supreme Court has stated, “[t]he

problems posed to the State[s] by illegal immigration must not be underestimated.”

Arizona, 567 U.S. at 389. If federal resources needed to enforce federal immigration law

are diverted from Illinois, other States will continue to bear the costs of illegal

immigration.

States are at risk of even more costs if violent protests are implicitly endorsed in

Illinois. Antifa-aligned groups seek to undermine the federal government as it works to

redress this significant problem by causing damage to federal property, harming federal

agents, and in some cases, damaging the city in which the riot is located—causing

significant damage to the state and its citizens. For example, the costs of the anti-ICE

riots in Los Angeles are estimated to have cost taxpayers $30 million. Chris Nesi, House

Judiciary Committee opens probe into taxpayer-funded group’s potential ties to LA antiICE riots, N.Y. Post (June 24, 2025, at 12:34 pm), https://nypost.com/2025/06/24/usnews/house-judiciary-committee-opens-probe-into-chirlas-possible-role-in-la-riots/.

Indeed, many reports suggest that much of the violence and destruction caused

by these riots can be traced to a few organizations funding the riots, see id., or

individuals moving between the States encouraging this type of behavior, see Wiley, et

al., supra, https://www.opb.org/article/2025/06/14/portland-police-ice-facility-riot/. 1

1 Indeed, this type of interstate movement has occurred before. Take for example the

riots that occurred in 2020. Destruction due to rioting occurred in at least 20 States,

9

The pervasiveness of these coordinated attacks cannot be underestimated. They

have resulted in the President declaring Antifa a domestic terrorist organization due

to its explicit “calls for the overthrow of the United States Government, law

enforcement authorities, and our system of law.” Designating Antifa as a Domestic

Terrorist Organization, 90 Fed Reg. 46317, 46317 (Sept. 22, 2025). To accomplish its

goals, Antifa organizes and executes a campaign to “obstruct enforcement of Federal

laws through armed standoffs with law enforcement, organized riots, violent assaults

on Immigration and Customs Enforcement [ICE] and other law enforcement officers,

and routine doxing of and other threats against political figures and activists.” Id.

Accordingly, aggression toward ICE is not a problem unique to Illinois. ICE faces

significant threats nationwide. Take for example the tragic shooting at a Dallas ICE

field office in September 2025, where a sniper opened fire and killed three people. “This

vile attack was motivated by hatred for ICE[.]” DHS Issues Statement on Targeted

Attack

on

Dallas

ICE

Facility,

DHS

(Sept.

24,

2025),

https://www.dhs.gov/news/2025/09/24/dhs-issues-statement-targeted-attack-dallas-icefacility. The shell casings that were found contained “anti-ICE messages on them,” and

handwritten notes by the shooter indicating he “hoped his actions would give ICE

agents real terror of being gunned down[.]” Id.; Holly Yan & Priscilla Alvarez, A 2nd

Jennifer A. Kingson, Exclusive: $1 billion-plus riot damage is most expensive in

insurance

history

and

rioters,

AXIOS

(Sept.

16,

2020),

https://www.axios.com/2020/09/16/riots-cost-property-damage, and some rioters moved

between jurisdictions. After rioting occurred in Minnesota in 2020, arrest records

showed that out of 18 people arrested in St. Paul, 6 were not from Minnesota, and out

of 109 people arrested in Minneapolis, 16 were not from another state. Trevor Hughes,

Protests in Minneapolis turned violent: Officials first blamed outsiders, but that’s not

what arrests show, USA Today (updated June 4, 2020, at 3:39 pm),

https://www.usatoday.com/story/news/nation/2020/05/30/george-floyd-protests-riotsviolent-outside-agitators-minnesota/5291658002/.

10

detainee — a father of 4 — dies after a gunman opened fire at an ICE office in Dallas,

CNN (Sept. 30, 2025), https://www.cnn.com/2025/09/30/us/dallas-ice-facility-shootingdetainee-dies.

Because this type of aggression toward ICE—targeting a specific facility and

preventing agents from being able to safely fulfill their duties—has already

necessitated the need for National Guard federalization in three States, it is imperative

that the unrest be squelched quickly to deter similar rioting in the other States.

Accordingly, the President’s action of federalizing the National Guard furthers

the public interest because it allows ICE agents to continue to perform their statutory

duties of identifying, apprehending, and removing illegal aliens, which is the only way

to protect the States from the harms caused by illegal immigration. Blackie’s House of

Beef, Inc. v. Castillo, 659 F.2d. 1211, 1221 (D.C. Cir. 1981) (“[T]he public interest in

enforcement of the immigration laws is significant.” (collecting cases)). And it protects

States from the costs incurred by violent protests and riots. Further, allowing the

federal government to quash this type of behavior at its outset sets a precedent

discouraging similar behavior in other States.

CONCLUSION

This Court should grant President Trump’s Application for Stay.

November 10, 2025

Respectfully submitted,

11

BRENNA BIRD

Attorney General

ERIC H. WESSAN

Solicitor General

1305 E. Walnut Street

Des Moines, Iowa 50319

(515) 823-9117

(515)281-4209 (fax)

eric.wessan@ag.iowa.gov

Counsel for Amicus Curiae

State of Iowa

AUSTIN KNUDSEN

Attorney General

CHRISTIAN B. CORRIGAN

Solicitor General

Counsel of Record

MONTANA DEPARTMENT OF JUSTICE

215 N Sanders

Helena, MT 59602

(406) 444-2026

christian.corrigan@mt.gov

Counsel for Amicus Curiae

State of Montana

ADDITIONAL COUNSEL

GENTNER F. DRUMMOND

Attorney General of

Oklahoma

ALAN WILSON

Attorney General of

South Carolina

STEVE MARSHALL

Attorney General of

Alabama

STEPHEN J. COX

Attorney General of

Alaska

TIM GRIFFIN

Attorney General of

Arkansas

JAMES UTHMEIER

Attorney General of

Florida

CHRISTOPHER M. CARR

Attorney General of

Georgia

RAUL R. LABRADOR

Attorney General of

Idaho

THEODORE E. ROKITA

Attorney General of

Indiana

KRIS KOBACH

Attorney General of

Kansas

RUSSELL COLEMAN

Attorney General of

Kentucky

LIZ MURRILL

Attorney General of

Louisiana

LYNN FITCH

Attorney General of

Mississippi

12

CATHERINE L. HANAWAY

Attorney General of

Missouri

MICHAEL T. HILGERS

Attorney General of

Nebraska

DREW H. WRIGLEY

Attorney General of

North Dakota

DAVE YOST

Attorney General of

Ohio

MARTY J. JACKLEY

Attorney General of

South Dakota

KEN PAXTON

Attorney General of

Texas

JOHN B. MCCUSKEY

Attorney General of

West Virginia