Preliminary Injunction Blocks Parts of Idaho’s Immigration Law

A federal judge has blocked parts of Idaho’s aggressive new immigration law allowing local police to arrest migrants over immigration status, dealing a significant blow to the state’s attempt to assert authority over what has traditionally been federal jurisdiction.

Quick Takes

Idaho’s House Bill 83 aims to let local police arrest migrants suspected of illegal entry if caught in another criminal act.
Federal Judge Amanda Brailsford issued a preliminary injunction, finding the law likely violates the Constitution and federal immigration authority.
The ACLU argued the law improperly tasks local officers with federal duties and raises due process concerns.
The Idaho law was modeled after a similar Texas immigration law passed in 2023.

Judge Blocks Enforcement of Idaho’s Immigration Law

In a significant legal development, U.S. District Judge Amanda Brailsford issued a preliminary injunction against parts of Idaho’s House Bill 83, also known as the Immigration Cooperation and Enforcement Act. The judge’s ruling effectively blocks the state from enforcing its new immigration measure, which aims to grant local law enforcement the authority to arrest individuals suspected of being in the country illegally when caught committing other crimes. Brailsford determined the ACLU demonstrated was likely to be successful on claims that the law violates the US Constitution’s due process clause and is likely preempted by federal immigration law.

The legislation, passed by Idaho’s Republican-controlled legislature, created new state crimes of “illegal entry” and “illegal reentry,” specifically targeting unauthorized immigrants and those who had been previously deported. The law classified unlawful state entry as a misdemeanor that could be elevated to a felony if the person was involved in another crime—potentially triggering deportation proceedings. Additionally, the legislation created the crime of “trafficking a dangerous illegal alien” and granted immunity to law enforcement officers from related lawsuits.

The law went into effect in March but was blocked almost immediately. Brailsford’s preliminary injunction keeps the law from being enforced as proceedings get underway.

Constitutional Concerns and ACLU Challenge

The ACLU of Idaho filed the lawsuit challenging House Bill 83, arguing that it improperly tasked local agents with federal duties and potentially violated constitutional due process protections. The civil liberties organization contended that the law attempted to supersede federal immigration enforcement by allowing local law enforcement to act as immigration agents—a role traditionally reserved for federal authorities. The ACLU also claimed the Idaho law would cause irreparable injury to those it represents, including individuals who might be profiled or detained based on perceived immigration status.

The ruling represents a significant setback for Idaho lawmakers who sought to take a more active role in immigration enforcement. Following the court’s decision, the Idaho Office of the Attorney General indicated they were reviewing their options, with spokesperson Damon Sidur stating: “The Attorney General’s Office is reviewing the decision to determine next steps. We will continue to defend House Bill 83 in full.”

Idaho’s legislation was modeled after a 2023 Texas law that has similarly faced legal challenges. The preliminary injunction will remain in effect while the case continues through the legal system. For now, Idaho law enforcement agencies are prohibited from making arrests under the new state immigration crimes, returning enforcement authority solely to federal immigration officials. The case highlights the ongoing constitutional tension between state autonomy and federal authority in immigration matters, a debate that will likely continue as states seek greater control over immigration enforcement within their borders.