The recent detention of Palestinian activist Mahmoud Khalil, a recent graduate of Columbia University’s School of International and Public Affairs, is troubling for many reasons. Khalil, a green card holder, has not been charged with any crime. The case against him seems to rest entirely on his political speech criticizing Israel. His arrest followed a week during which people targeted him intensely online, calling for deportation, suggesting a world in which the political wishes of right-wing extremists are translated into state policy. His rapid removal to Louisiana, far from his lawyers, his friends, and his eight-month-pregnant wife, reeks of disappearances of student radicals in authoritarian nations throughout history.

But for all that is truly novel about his situation, Khalil’s case is also a reminder of the long US history of deportation and border control as a strategy to punish political radicals and quell dissent. The most famous episode of mass deportation as a tool of political repression came during the Red Scare of 1919 to 1920. During the period of intense social upheaval that followed World War I, general strikes swept cities like Seattle, and the specter of the Bolshevik Revolution haunted American politics. In the spring of 1919, an anarchist faction sent bombs in the mail to the homes of important political figures, including that of Attorney General A. Mitchell Palmer.

While flyers distributed with the bombs were traced to a print shop operated by the followers of one radical thinker known for advocating violence, there was never enough evidence against any individual to mount a criminal case. Instead, in late 1919 and early 1920, Palmer ordered a series of raids of political meetings of radical organizations. Thousands of people were arrested and detained, some with warrants and some without, and more than 550 were ultimately deported.

Palmer insisted that these deportations were necessary to protect the American population. His argument was that the social unrest in the country, far from being a response to unemployment, inflation, or racism, was being stirred up by a network of “criminal aliens,” almost exclusively from Russia and Germany, who had “infected our social ideas with the disease of their own minds and unclean morals.” Because the government was charged with fighting crime, it could legitimately round up these actors and expel them from the nation — even if as individuals they were not linked to any acts of violence.

Although the raids were widely condemned, they had a profound impact. The argument that immigrants brought dangerous politics and radical violence to the United States helped prompt Congress to pass the Johnson-Reed Act in 1924, sharply curtailing immigration from Southern and Eastern Europe.

The threat of deportation and the control of the border also played an important role in the anti-communist crackdown of the 1950s. In 1952, Congress passed the Immigration and Nationality Act. The law contained provisions that permitted the State Department to deny passports to US citizens who were members of the Communist Party or who refused to sign affidavits testifying that they were not and had never been Communists.

It also expanded the government’s powers to interrogate the political sympathies of people wanting to immigrate to the United States, a move that was widely understood as an effort to block Eastern European Jews who had been displaced by the Holocaust from entering the country on the pretext that they supported the Soviet Union. (For this reason, most Jewish organizations opposed the bill, and President Harry Truman vetoed it; Congress passed the act over his veto.)

Finally, it authorized the federal government to deport “aliens” whom the secretary of state believes might have “seriously adverse foreign policy consequences” for the United States, and to bar from naturalization and deport immigrants who advocated “world communism” or belonged to organizations that did. This was not an idle threat: the Trinidadian-born Communist activist Claudia Jones, threatened with deportation under the law, left the country voluntarily in December 1955 after being detained at Ellis Island (which was, by that time, used as a detention camp as well as still serving as an entry point for new immigrants).

This is the law that the Trump administration is now drawing on in its case against Khalil, whose story reminds us that border control has always been, at least in part, about political control. It is a fiction that immigrants bring dangerous political ideas into a nation that would be harmonious if only for their presence. Ideas, after all, move easily across barbed wire and concrete walls.

From the early twentieth century to the present, native-born Americans have found plenty to criticize in their country. Punishing people who are more vulnerable for reasons of their legal status by removing them from the body politic is a form of political coercion and an attempt to stifle dissent — not only among international students, green card holders, and immigrants, but the whole population. And the use of the 1952 anti-communist law to threaten Khalil is also a reminder that repressive legislation, once passed in a particular political context, has an impact that lingers long after. Even long dormant, its coercive power can be revived.