Beyond the Border: How enforcement powers inside a 100-mile zone affect Milwaukee’s immigrant families

Under a federal regulation enforced by U.S. Customs and Border Protection, an agency within the Department of Homeland Security, authorities claim an extended reach of 100 miles into the interior from any land or maritime U.S. boundary.

The result is that more than 200 million people, or about two-thirds of the nation’s population, live in what immigration advocates often call the “100-mile border enforcement zone.” Lake Michigan, which defines much of Wisconsin’s eastern boundary, places the City of Milwaukee well within CBP’s purview.

DEFINING THE 100-MILE ZONE

CBP, which includes the Border Patrol, is the largest law enforcement agency in the nation. Since 1946, its jurisdiction has steadily expanded to grant officers powers unlike those of other federal agencies.

A federal statute gave CBP the authority to stop and search vehicles within a “reasonable distance” of the border. By regulation, that distance was defined as 100 miles from any land or maritime boundary.

Over decades, the seemingly small phrase of “reasonable distance” has snowballed into an expansive law enforcement mandate. Officers can board public transportation, set up checkpoints, and stop, question, or detain people without the usual restraints placed on policing in the interior of the country.

In other words, constitutional protections under the Fourth Amendment, which ordinarily require warrants or at least reasonable suspicion for searches and seizures, have been interpreted more leniently within the 100-mile zone.

HISTORICAL CONTEXT AND KEY COURT CASES

The Supreme Court cases that shaped such a dynamic span decades. One pivotal example is “Almeida-Sanchez v. United States” (1973). While the Court initially ruled that a car search by immigration officers without a warrant or probable cause was unconstitutional, Justice Lewis Powell’s concurrence opened the door to expanded authority in border areas.

He floated the idea that special “area warrants” could essentially suspend usual Fourth Amendment requirements for border enforcement. A few years later, “United States v. Brignoni-Ponce” (1975) lowered the standard for roving Border Patrol stops in the 100-mile zone to “reasonable suspicion.”

The justices also allowed race to be factored into an officer’s decision to stop a driver, effectively sanctioning racial profiling. Another ruling, “United States v. Martinez-Fuerte” (1976), upheld random highway checkpoints at which agents stop vehicles to question occupants about their immigration status, again without individualized suspicion.

Subsequent decisions have reinforced those rulings. “Arizona v. United States” (2012) partially upheld an Arizona law that deputized local police to check immigration status, effectively blending immigration enforcement with local policing.

For immigrant communities, including those in Milwaukee, such cases have fueled concern that they are double-policed, by both local authorities and federal agents who hold expanded border powers.

CBP’S EXTRAORDINARY REACH

CBP’s authority stands out not only because it reaches so far into the interior but because it bypasses many of the usual legal standards for searches and seizures. Other federal agencies typically must present a warrant or clear probable cause to stop and search someone’s vehicle or detain people.

Border Patrol, however, exerts powers that immigration advocates say encourage racial profiling and abusive tactics. Officials within CBP and the Border Patrol insist that the measures are necessary to manage unlawful crossings and national security concerns.

They argue that by casting a wide enforcement net close to border entry points, they can stem the flow of drugs, thwart human trafficking, and respond quickly to potential threats. Critics, though, say the arguments have led to routine violations of civil rights, especially in urban areas that happen to fall within the 100-mile zone.

WHY MILWAUKEE IS INCLUDED

Milwaukee, with its shoreline against Lake Michigan, is unequivocally part of the zone. While Milwaukee is about 90 miles north of the Illinois state line, it is also bounded by a maritime border, which triggers CBP’s 100-mile rule.

That also puts most of southeastern Wisconsin squarely in a region where federal law enforcement has enhanced authority. Nearby cities like Racine and Kenosha face the same designation.

Although Milwaukee may not be a border crossing in the conventional sense, as compared with ports of entry in states along the southern U.S. border, it falls under a category federal officials label as “border cities.”

Milwaukee residents have sometimes encountered CBP activities in everyday settings like on an MCTC Bus, at Amtrack’s Intermodal Station, or at random checkpoints on major highways. Civil liberties organizations point out that those law enforcement practices take place with minimal oversight, raising questions about racial profiling of Hispanic residents and other minority communities.

IMPACT ON WISCONSIN’S IMMIGRANT POPULATION

Wisconsin’s Hispanic population has grown steadily over the past few decades, with Milwaukee County home to a substantial share. Many families have lived in the region for generations. Others arrived more recently, seeking job opportunities in manufacturing, hospitality, or agriculture. Advocates say the 100-mile zone enforcement makes them a frequent target for stops or questioning.

“People are worried about taking their kids to school, going to the grocery store, even showing up for medical appointments,” said a community organizer with a Milwaukee-based immigrant rights group who identified herself as Maria. “In many instances, we have seen CBP agents board Greyhound buses or linger near highway checkpoints, asking passengers about their legal status.”

She said those actions stoked fear in entire neighborhoods, as individuals became wary of routine activities.

“We have a community where some people just avoid any public setting because they don’t want to encounter an immigration officer who might take them into custody,” she added.

Parents in particular have expressed concerns that their children would be questioned, or that family members lacking documents could be apprehended. Several local groups participate in awareness campaigns, handing out booklets that explain legal rights during encounters with immigration agents. However, according to advocates, the sweeping authority of border enforcement often overrides typical Fourth Amendment protections.

BORDER PATROL’S DEFENSE

CBP officials say their policies are vital to national security. They maintain that within the 100-mile zone, the agency focuses on law enforcement priorities including human smuggling and drug trafficking. “These guidelines are necessary so our agents can address threats close to the border before they disperse deeper into the interior,” said a CBP spokesperson, speaking on condition of anonymity because they were not authorized to speak publicly.

When pressed about allegations of racial profiling or intrusive methods, the spokesperson pointed to internal regulations that purportedly limit abuses of power.

“We have zero tolerance for racial profiling,” the spokesperson said, adding that officers receive training on civil rights and legal standards. “Every search or seizure must be conducted under a legal framework, and we have procedures to investigate any misconduct claims.”

Still, critics say the agency’s internal reviews have rarely led to accountability. They also highlight a February 2020 move by the Trump administration that granted CBP immunity from certain Freedom of Information Act requests. Immigration rights advocates regard that exemption as a shield against transparency, making it harder for the public to learn about potentially problematic enforcement operations.

CALLS FOR LEGISLATIVE REFORM

In the broader legal landscape, the courts have historically deferred to federal agencies, citing national security and the federal government’s authority over immigration. Activists argue that the Supreme Court has gone too far in allowing a “patchwork” approach to constitutional protections.

They say two-thirds of the country effectively lives under a diluted version of the Fourth Amendment. Some members of Congress, particularly those representing districts along the southern border, have introduced legislation to limit or abolish the 100-mile rule.

One proposal calls for narrowing CBP’s interior enforcement zone to 25 miles and imposing stricter guidelines for searches. Another would require warrants for searches of private property, including homes. Those efforts have faced uphill battles in a polarized Congress where immigration enforcement is a divisive issue.

DOOR-TO-DOOR RAIDS

Beyond routine patrols, CBP’s powers have been deployed in other controversial ways. In early 2020, then-President Donald Trump announced that BORTAC, an elite Border Patrol tactical unit, would be sent to major cities, including Chicago and possibly others in the Great Lakes region, to assist Immigration and Customs Enforcement in raids.

For cities like Milwaukee, advocates say that Trump’s return to power in 2024 heightens the specter of armed officers making door-to-door arrests in predominantly Hispanic neighborhoods. No other federal law enforcement agency has the power to simply roll in to quell protests using security rationales that are so loosely defined at best.

A HISTORY OF WELCOMING IMMIGRANTS

Legal scholars say that short of a major change in Supreme Court jurisprudence or congressional action, the 100-mile zone is unlikely to be rolled back. Immigration reform bills introduced over the years have only occasionally addressed border enforcement rules, and many lawmakers remain hesitant to appear soft on border security issues.

Activists in Milwaukee point out that the city has a history of welcoming immigrants. Community centers in the south side’s Hispanic neighborhoods offer legal clinics and “know your rights” workshops.

Churches stand ready to serve as sanctuaries for those afraid of being deported. Local nonprofits have joined national coalitions calling for legislation they say would help realign border enforcement with traditional constitutional standards.

But the tension between federal law enforcement and civil liberties remains firmly in place. Milwaukee’s inclusion in the 100-mile enforcement zone underscores a lesser-known reality. A resident does not need to live in a traditionally recognized border region to be subject to these extended powers.

Milwaukee, and many other cities on coastlines, stands as a reminder that the constitutional landscape can change dramatically with nothing more than a 100-mile line on a map, an invisible border that places ordinary Americans under extraordinary scrutiny.