Federal agents have begun to withdraw from Portland, Oregon, where they were stationed to protect federal property and personnel amid protests in the city, despite objection by local leaders. But, their authority to be there in the first place has deep roots.

Legislation passed just after the terrorist attacks on Sept. 11 designed to protect the U.S. from national security threats; and judicial expansion just after the Civil War designed to ensure southern states adhered to Reconstruction-era laws provide the framework for what we see today, says Northeastern law professor Michael Meltsner.

“Federal presence in Portland is both authorized and problematic,” says Meltsner, who is the George J. and Kathleen Waters Matthews Distinguished University Professor of Law.

Authorities in the Trump administration say that the federal agents, who were deployed by the U.S. Department of Homeland Security earlier this month, are in Portland to protect federal property and personnel. The federal force is composed of officers from Customs and Border Protection, the Transportation Security Administration, the Coast Guard, and Immigration and Customs Enforcement who back up the Federal Protective Service, which is already responsible for protecting federal property, according to The New York Times.

On July 29, Oregon Gov. Kate Brown announced that the forces would begin withdrawing from the state beginning July 30.

The federal agents arrived after weeks of protests in the city against racial injustice—protests that had already been met with aggressive tactics from local police that were criticized by local officials including the governor, speaker of the Oregon House of Representatives, and some city councilors.

President Donald J. Trump has also threatened to send as many as 75,000 federal agents to other U.S. cities to quell protests there as well, even as local authorities in Portland, including Brown and Portland Mayor Ted Wheeler, have implored the agency to stand down, and the Oregon attorney general and the American Civil Liberties Union, a civil rights group, have sued.

But federal officials say they have clear authority. Representatives from Customs and Border Protection cited a section of the Homeland Security Act of 2002, legislation passed after the terrorist attacks on Sept. 11, 2001.

The act gives the U.S. secretary of Homeland Security the authority to “protect the buildings, grounds, and property that are owned, occupied, or secured by the federal government… and the persons on the property.” The law was designed to protect the U.S. national security threats such as those perpetrated on 9/11, Meltsner says.

The agents in Oregon were there ostensibly, then, to protect federal property—including the federal courthouse in downtown Portland—from protesters, he says.

“To the extent that this is all they were doing, it would seem non-controversial,” Meltsner says.

But news media reports from the city show what appear to be plain-clothes federal agents forcing protesters into unmarked vans.

If that were the case, Meltsner says, the agents would be in violation of the Fourth Amendment, which protects U.S. citizens against unreasonable searches and seizures.

“In that case, just because federal agents have nominal authority under a federal statute, it doesn’t mean that they can violate people’s constitutional rights under the Fourth Amendment,” Meltsner says. “From what I’ve read in the papers, it would appear that these federal agents are interfering with the liberty of the people without any cause.”

A state official could decide to take a federal agent to court over an alleged violation. Often, however, such cases are not tried in a state courthouse, they’re removed to the federal court system to be tried—or, as is often the case, dismissed—there, Meltsner says.

This act of removal is a judicial power that was created during the Reconstruction period in the U.S., roughly 1863 to 1875. During the years after the Civil War, progressive congressmen passed legislation that would ensure the rights of formerly enslaved people in the country—including the passage of the Fourteenth Amendment—and sent federal agents to various Southern states to enforce that legislation.

White officials in those Southern states, reluctant to apply the new legislation to formerly enslaved people in their states, tried to find ways to prosecute the federal agents enforcing the laws, Meltsner says. In order to protect the agents and the rights of Black people, Congress allowed cases that had begun in state courts to be taken out of them and tried in federal courts, where they were often dismissed, he says.

Now, Meltsner says, the same tactics may be used to protect the federal agents allegedly acting unlawfully in Oregon.

“Basically, what’s happening in Portland now could ultimately involve the same tactics used by the Justice Department to protect these federal agents during Reconstruction and the Civil Rights movement,” Meltsner says.

And, he adds, although the focus on federal intervention in the city is warranted, it’s just as important to examine the behavior of the city and state police before federal agents arrived.

“Based on the news reports, it would appear that there was an incredible amount of First Amendment and Fourth Amendment violation from the Portland Police Department,” Meltsner says. “This is certainly an evolving situation, with a lot of questions to be answered about what, exactly, is going on.”

For media inquiries, please contact Jessica Hair at j.hair@northeastern.edu or 617-373-5718.