Donald Trump's attempt to control the US Justice System is alarmingly similar to Hitler's strategy in Nazi Germany

Throughout his presidential campaign, Donald Trump described his opponent, Hillary Clinton, as a criminal and said she should be tried and put in jail (of her guilt, he had no doubt). Commentators at the time noted the extreme nature of such rhetoric and the fact that demands for the investigation and imprisonment of political opponents was alien to the American system. But, they speculated, perhaps it was just that — rhetoric — and with his inauguration as President, he would leave such dangerous talk behind.

It turns out, however, that Trump has proven unable to let go of his obsession with his defeated rival. In early November 2017 — nearly one year after his election victory — he was not only continuing to attack Clinton, but also calling on the FBI and the Justice Department to investigate her. He was “very frustrated” by the fact that he was unable to order those agencies to “go after” his former opponent — something he said he would very much love to do.

It was a horrifying moment as the President of the United States, perhaps more clearly than at any previous time, expressed the thoughts and desires of an autocrat. And with the announcement that Attorney General Jeff Sessions will explore the possibility of creating a new special counsel to investigate Hillary Clinton, those thoughts and desires have moved that much closer to being realised.

Such open calls for criminal investigations of political opponents are truly unprecedented in American history — and for good reason, since they would undermine the very foundation of liberal democracy. If the president could order the FBI to investigate Hillary Clinton, where would it stop? Anyone who spoke out to criticise such a brazen act would be vulnerable to the same treatment. And then any individual or any group — regardless of whether they had actually done anything — would be at the mercy of Trump’s politicised justice system. The President would be able to exclude anyone he wished from the national community. The road to dictatorship would be wide open to him. We know this because it was such a system that helped destroy democracy in Germany and helped Hitler establish his Nazi dictatorship.

One of most significant challenges the new Weimar Republic faced was a politicised judicial system — an important element in the weakening of German democracy. One of the key failings of the revolution that toppled the German Empire in 1918 was the failure of the revolutionaries to establish a truly republican judiciary by allowing the judges from the old imperial system to remain on the bench. These were men who’d been trained and established their careers under the old authoritarian system. They had no sympathy for the new liberal, democratic regime. And the verdicts they rendered made this exceedingly clear. Political crimes committed by individuals on the left consistently received longer prison sentences than those committed by people on the right.

The best-known example of this skewed system of justice is the case of Adolf Hitler. Arrested in 1923 after having attempted to overthrow the government, he was tried and convicted of treason. The conservative judge sympathised with the young Nazi leader’s goal, if not with his methods, and therefore sentenced him to a mere five years in a rather comfortable prison. He would end up serving only nine months.

A justice system that openly flouted the republic’s liberal, democratic values seriously undermined the government’s legitimacy and gave hope to those who continued to work for its destruction. In less than a decade, the battered republic would succumb, thanks in no small measure to the aid and comfort provided to the forces of the right by a politicised illiberal, anti-democratic system of justice. Under Hitler, the justice system became a tool for the establishment of his dictatorship and for the policies of exclusion he pursued.

Immediately after coming to power, Adolf Hitler targeted his main political opponents: the German Communist Party. With his fellow Nazi Hermann Goering heading the Interior Ministry, members of the SA were now deputised as auxiliary police and, along with the traditional police forces, tasked with the assault on Germany’s communists. Storm Troopers attacked communists in the streets, arrested them, and brought them to makeshift jails where they beat, tortured, and sometimes killed them.

After the communists, it was the Socialists’ turn to experience Hitler’s brand of justice. Those not beaten or tortured to death were driven underground, into exile, or were sent to the new concentration camps being built and operated by the SS.

To the new Chancellor, the communists and socialists were not simply political opponents. They were enemies, traitors who had already betrayed the nation in the First World War and toppled the old regime in revolution. As a result, those who participated in this bloody state-sponsored rampage would face no legal consequences. Not only that, but “enemies” accused of crimes could face punishments far more severe than the law would normally allow.

The man accused of setting the Reichstag building ablaze as the first step in a communist uprising, for example, should have faced a straightforward prison sentence. But Hitler’s desire for what he considered justice led him to pressure the Justice Minister Franz Gürtner (also a judicial holdover from the Empire) to write a new law — an ex post facto law that made the alleged arsonist’s crime a capital offense.

Hitler had begun to subvert the law to serve his political goals. Police and judicial authority had to be subordinated to the will of the leader. A politicised justice system would allow him to target and eliminate any and all groups he considered outside the bounds of the German national community.

One of the most important steps for any would-be autocrat is to gain control of the justice system and turn it into a tool for the elimination of any and all opposition. Normally that’s something that Americans observe from a distance — in the pages of history books or newspapers telling of coups and show trials and the exiling or execution of political challengers in some distant country or from some other period. Perhaps such distance has lulled Americans into a false sense of security. That’s something that only happens “over there,” or “back in those times.” The American tradition of liberalism and democracy will protect us. We’re exceptional.

But it’s precisely that self-confidence — more like self-delusion — that can work to Donald Trump’s advantage. His clearly anti-democratic statements and wishes can be shrugged off as mere rhetoric. How many people early on dismissed Hitler as a buffoon? How many people doubted he’d last any longer in office than his two most recent predecessors?

Far more quickly than anyone would have imagined possible — helped greatly by the unforeseen Reichstag fire — Hitler had succeeded in bending the courts and the police to his will. By that point it was too late. German democracy was not destroyed in a coup or a violent revolution. It was undermined from within. Circumstance and Hitler’s determination did the rest.

Richard E Frankel is associate professor of modern German history at the University of Louisiana at Lafayette and the author of Bismarck's Shadow. This piece originally appeared on History News Network