With the marshals under attack, Kennedy deployed first the Mississippi National Guard and then thousands of federal troops as well. (That military operation, codenamed RAPID ROAD, was actually the first and only time during the Cold War that the military activated and used plans it had developed to quell civil disturbances in the wake of a nuclear attack.)
Then, in 1963, Kennedy again relied on the National Guard to help with the integration of the University of Alabama, and his successor, Lyndon Johnson, used marshals and the National Guard to protect civil rights marchers in Selma after Alabama state troopers infamously attacked them at the Edmund Pettus Bridge in an incident that came to be known as “Bloody Sunday.”
Presidents began using military troops, including the National Guard, more routinely in America’s cities in the 1960s. During summer riots following police brutality in Detroit in 1967, President Johnson ordered elements of the 82nd and 101st Airborne Divisions into the city and Michigan governor George Romney called up the Michigan National Guard; more than 40 people were killed, more than half by Detroit police. National Guard troops killed 11, including a four-year-old girl, Tanya Blanding, who died when a Michigan guardsman opened fire with a tank-mounted .50-caliber machine gun on her apartment after wrongly believing a sniper was inside.
While troops were used again amid the 1968 riots that followed the assassination of Martin Luther King, Jr., the downside and risk of such deployments was vividly captured two years later at Kent State University when National Guard troops opened fire on students protesting the Vietnam War, killing four and wounding nine.
Over the years since there has been incredibly limited domestic use of federal troops—the Los Angeles riots of 1992 being one exception—and presidents and attorneys general until the Trump administration usually go out of their way to coordinate surges of federal law enforcement to cities or states.
Even during the peak of the marshals and troop deployments to the South amid the civil rights movement, presidents only acted after state officials either refused to quell violence targeting Americans practicing their constitutional rights or, in the case of the Alabama state troopers, were the cause of the violence against peaceful citizens themselves. Often, a president acted only after there was defiance on the ground of a lawful court order—ensuring that there was a second branch of government acting as a check-and-balance and trigger for such federal action.
While Trump has said that the immigration enforcement effort in Minneapolis—as with previous efforts in Los Angeles, Washington, DC, Chicago, Charlotte, Portland and, most recently, Maine—is meant to enforce “law and order,” there’s no apparent rhyme, reason, or necessity to deployments beyond political terror.
Trump today is attempting something unprecedented that stands in contravention of all historical tradition in the United States: the brutal application of federal forces against a state and region with no apparent reason beyond it being led by members of the political opposition.
In deploying immigration officers and border security agents from DHS, rather than deputy US marshals from the Department of Justice—as presidents in the past have done—Trump is also changing the nature and tenor of his federal force. Marshals, whose work and training involves constitutional rights and protections, have always been used to protect civil rights and valid court orders and come with strong federal policing powers and authorities. The agents from Customs and Border Protection (CBP) and Immigration and Customs Enforcement (ICE) are different. They are not trained to normal federal law enforcement standards of dealing with the public and are meant to operate with severely limited authority to enforce immigration matters, not general federal laws. CBP agents in particular are less a regular law enforcement agency, grounded in due process, and more a paramilitary force meant to operate on the border regions. They were never intended to have regular contact with US citizens and civilians.
Trump has also attempted to use troops in similar crackdowns over the last year and been stymied by federal courts, who, among other instances, preliminarily blocked his federalization of the California National Guard.