Opposing policies over immigration and sanctuary cities define the contemporary debate over federalism

Disputes between the federal government, Republican-controlled states, and Democratic-controlled cities over immigration enforcement and sanctuary policies have become a central flash point in modern federalism. These conflicts will shape the future of state autonomy, federal authority, and the enforcement of national policy across jurisdictions.

Sharp partisan divides shape how Americans view immigration enforcement

A January 2026 survey shows large party gaps: Both sides broadly support recording arrests, but Democrats are much more likely than Republicans to support sharing officer locations and to oppose profiling, masked officers, and neighborhood-based enforcement.

Sanctuary cities limit local cooperation with federal immigration enforcement

Sanctuary cities limit how local agencies help ICE—such as restricting detainers, jail transfers, or data sharing—while still enforcing criminal law, leaving immigration enforcement mostly to federal authorities.

Federalism creates tension between national and state power by design

Federalism assigns authority so that neither the national government nor the states entirely dominate the other or the people they govern. By creating overlapping claims of power, the system makes negotiation, conflict, and compromise a permanent feature rather than a failure.

Courts referee federalism disputes between Congress and the states

Modern federalism is primarily worked out through litigation. The Supreme Court decides disputes in written opinions that explain when federal law preempts state authority, how far Congress's powers extend, and when states may resist.

Both parties largely agree that America's immigration system is broken

This three‑part podcast series traces America's immigration system origins, revealing how historically celebrated Ellis Island-era policies evolved into today's fractured, fact‑starved debate—shedding light on economic, cultural, and political forces shaping the current dysfunction.

Federal systems are a minority among the United Nations' 193 members

Of the United Nations' 193 member countries, roughly two dozen use a federal system, dividing power constitutionally between national and subnational governments. This group includes the United States, India, Canada, Germany, and more. The video walks through examples of how these states operate.

Immigration and Customs Enforcement handles immigration enforcement within the interior of the US

ICE operates inside the United States, enforcing immigration laws through investigations, arrests, detention, and deportation of individuals residing in the country illegally. This page provides an overview of the agency's mission, structure, and internal enforcement operations.

Track the changes in US immigration law throughout history

This interactive timeline tracks the development of US immigration law, overlaid with time-series data on percentages of the foreign-born population. Explore how each major policy development correlated with immigration levels, revealing the relationship between legislation and demographic change.

A timeline of US immigration laws

The United States began regulating immigration soon after it won independence from Great Britain, and the laws since enacted have reflected the politics and migrant flows of the times. Here's a timeline of key immigration laws from 1790 to 2014, according to the Pew Research Center.

Issues of ICE conduct span multiple Republican and Democratic administrations

Complaints of abuse and harsh treatment increased as detentions and deportations of undocumented immigrants reached record levels during former President Barack Obama's first term. Frontline investigated the causes of these claims in 2011 and found that these issues cross party lines.

The Department of Homeland Security manages America's border and immigration enforcement

DHS serves as the umbrella agency managing immigration enforcement, border security, and related public safety responsibilities. Learn more about the department's budget, strategic initiatives, organizational history, and coordination of multiple agencies.

Immigration courts are part of the DOJ, not the judicial branch

Unlike federal courts, immigration courts operate under the DOJ's Executive Office for Immigration Review—meaning immigration judges are DOJ employees, not independent judicial officers, and their decisions can be reviewed and overturned by the attorney general.

States are increasingly using preemption laws to override local decisions

Preemption laws enable state legislatures to prevent cities and counties from enacting their own rules on issues like minimum wage, gun control, and housing. Their use has increased significantly in recent years.

The debate over federalism helped produce the novel character of the United States

During ratification, Federalists argued that a strong national government was essential for national survival. Anti-Federalists warned that it could overwhelm states and threaten individual liberty—forcing compromises that shaped early American federalism and led to the adoption of the Bill of Rights.

Supreme Court Justice Louis Brandeis once called states 'laboratories of democracy'

Louis Brandeis argued that federalism allows states to experiment with new policies without committing the entire nation, thereby allowing successful ideas to spread while limiting the risks of failure.

Explore the countries with a federal system—and see how they work

This resource from the Forum of Federations catalogs the world's federal countries. It provides background information on each, including the emergence of federalism, the division of power, and the practical interaction between national and regional governments.

Visually explore the federal government's evolving role in education.

The 2025 budget bill significantly increased ICE's budget and role in federal law enforcement

The 2025 'Big Beautiful Bill' allocated $170B to immigration and border enforcement for use through 2029. ICE's nearly $100B share includes substantial increases in detention capacity and operational scope. The increased funding will make ICE the most heavily funded federal law enforcement agency.

The United States is the world's oldest continuously operating federal system under a written constitution

The US pioneered federalism in the late 18th century, and many countries later adopted federal systems to manage conflict and share power. This resource features interactive maps that trace the spread of federal systems worldwide from 1900 to the present.

Policies related to the coronavirus pandemic inadvertently increased illegal border crossings

A pandemic-era public health measure called Title 42—intended to seal the border by expelling migrants immediately—backfired. Because expulsions carried no legal consequences, migrants simply tried again, driving illegal crossings to a peak of over 370,000 people in December 2023.

Hear from those who reported on the ground in Minneapolis amid immigration raids

In this podcast episode, journalists reporting from Minneapolis describe ICE enforcement actions, street protests, and community fallout—offering firsthand accounts of how immigration crackdowns are unfolding in the Midwestern city.

US immigrants shifted from primarily originating in Ireland and Germany to Mexico and India.

Before 1965, US immigration law relied on nationality-based bans and quotas.

See how the executive branch of the US government works

The executive branch enforces federal laws and is led by the president, who serves as head of state, commander in chief, and chief diplomat. Supported by the vice president, Cabinet, and around 4 million federal employees, it carries out laws through 15 departments and dozens of agencies.

Studies show immigrants commit crimes at lower rates than native-born Americans

Research examining incarceration records and crime data generally finds that immigrants—including undocumented individuals—have lower crime and incarceration rates than US-born citizens, though measurement is limited by gaps in national data on immigration status.

Federalist 51 argues that liberty could be protected within the national government

In Federalist 51, James Madison wrote that separating powers and pitting their ambitions against one another would restrain federal overreach from within, reducing reliance on state resistance as the sole check on national authority.

Watch the DOJ attempt to reform a local police department in 2016

This report examines federal oversight of Newark's police department as the DOJ enforces reforms following its investigation into civil rights violations, highlighting the challenges of reforming local policing through federal intervention.

The New Deal shifted economic and social authority to the federal government

Franklin D. Roosevelt's response to the Great Depression expanded federal power through economic regulation and social welfare programs, permanently reshaping federalism by shifting responsibility for financial security to Washington while leaving states to administer many of these programs.

See how local, state, and federal governments divide the cost of public services

Federal, state, and local governments share responsibility for funding public services. Education, roads, and social programs are funded through a complicated mix of taxes and intergovernmental transfers.

Thousands of state voting changes have been federally blocked since the Voting Rights Act

Since 1965, federal oversight has blocked thousands of state-level voting changes—including redistricting plans—by requiring approval for measures that could affect minority representation, a process scaled back by the Supreme Court in 2013.

Colonial self-rule fostered strong autonomy and distrust of centralized power

American colonies were governed through a patchwork of different systems, ranging from Crown-run to locally controlled. Broad local autonomy—often followed by sudden imperial crackdowns—taught colonial leaders to prize home rule and distrust distant centralized power, attitudes that later informed US federalism.

The Supreme Court limited federal judges' power to issue nationwide injunctions in 2025

In a 2025 decision arising from litigation over a presidential order on birthright citizenship, the Supreme Court held that individual federal judges may not nationwide block executive policies—curbing the use of sweeping injunctions and reshaping how constitutional challenges proceed through the courts.

Multiple legal pathways exist for immigrating to the United States

This comprehensive guide outlines various routes to US immigration, including family-sponsored and employment-based visas, as well as humanitarian protections. Navigate the complex American immigration system and understand the options available to prospective immigrants seeking legal entry.

The supremacy clause establishes federal law as the highest authority

The supremacy clause states that the United States Constitution and federal laws enacted under it supersede conflicting state laws, ensuring national authority prevails when federal and state governments disagree.

An adultery and poisoning case examined whether federal treaty power supersedes state law

This Radiolab podcast unpacks Bond v. United States, where a local love-triangle assault became a federal case under an international treaty—forcing the Supreme Court to confront a founding question: How far can federal power reach into crimes traditionally handled by the states?

The Supreme Court has greatly expanded executive power in recent years

In Trump v. United States, the court ruled that a former president enjoys absolute immunity for "official acts" in his constitutional core powers. In Trump v. CASA, Inc., the court limited federal courts' ability to block executive enforcement through nationwide injunctions—decisions that shifted power toward the executive branch.

President Trump has changed decades-long norms for the DOJ during his second term

The Trump administration made changes to ethics oversight, instructed US attorneys to coordinate with the White House, dismissed cases, and overhauled the career hiring process in the Civil Rights division. The administration asserts these changes were justified and aimed to end what they claim as the weaponization of government.