Ruth Ben-Ghiat is a frequent contributor to CNN Opinion, a professor of history and Italian studies at New York University who writes about authoritarianism and propaganda. The opinions expressed in this commentary are solely those of the author.

(CNN) Montana's starting to look more like Moscow, after then-Republican House candidate Greg Gianforte's assault Wednesday on Guardian reporter Ben Jacobs. As the Guardian reported and a Fox News reporter in the room confirmed, Gianforte allegedly grabbed Jacobs and slammed him to the ground. This incident comes on the heels of other instances of political reporters facing physical intimidation and arrest for doing their jobs -- which is the persistent questioning of public figures.

Gianforte's action may cost him personally: he's been charged with misdemeanor assault and he lost some key endorsements -- though he managed to win anyway in a state where Republicans have held the House seat for more than 20 years. Yet there's a bigger picture to consider -- this is also a perfect storm for the GOP. It highlights the expressions of violence that permeate a party that is dangerously dependent on the National Rifle Association, supports militia groups who elsewhere might be considered dangerous insurgents, and backs those who use violent speech -- such as several state GOP lawmakers who called for Democratic Party Presidential nominee Hillary Clinton to be killed.

But this incident also shows how effective President Donald Trump's attempts to criminalize the media have been, and how his glorification of strongmen sets the tone for everyday behavior by the rank and file.

Donald Trump came out swinging at journalists from the very start of his presidential campaign. He labeled journalists as dishonest jackals out to smear all that was decent -- him above all. At his rallies, he treated the press as though they were suspects, penning them behind security barriers and trying to intimidate them. Trump even backed up his campaign manager, Corey Lewandowski , after he roughed up Breitbart reporter Michelle Fields at a rally in March 2016.

It's just as well that National Public Radio and other media outlets offered reporters on the Trump beat the kind of threat-awareness training normally given to those who cover conflict zones abroad. Gianforte's alleged assault on Jacobs -- after asking a question about the CBO report on the impact of the Republican health care bill -- shows they may need it. And how can it be otherwise, when Trump spent so much energy training his followers to hate them? "Rope. Tree. Journalist. Some Assembly Required," reads a T-shirt still popular at Trump events.

As someone who writes about authoritarians, I'm not surprised that President Trump would like to take the next step of jailing journalists, as a leaked memo given to former FBI director James Comey reveals. Then the real sport can begin, out of sight.

Donald Trump has been open about his admiration for foreign strongmen who repress their critics, including journalists, and behave in ways that make clear they consider themselves above the law. Trump's fawning over Russian President Vladimir Putin is well known. And all Americans should read the transcript of Trump's phone conversation with Philippine President Rodrigo Duterte, in which he praises Duterte's " unbelievable job on the drug problem ." Our leader compliments Duterte, a man who in his country's drug war has gotten away with oppression, including alleged complicity in thousands of extra-judicial killings.

To be fair to Donald Trump, he was not present in Montana. Gianforte, a wealthy businessman, reportedly escalated his encounter with Jacobs to physical aggression all on his own. "I'm sick and tired of you guys," he can be heard shouting on a recording of the incident, as he allegedly body-slammed the reporter. Thank you, Mr. Gianforte, for demonstrating so clearly the workings of prejudice: one person stands in for the entire hated category.

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Gianforte's alleged assault on Jacobs also shines light on a more immediate GOP problem: how to deal with the spreading fallout from our government's investigation into the Trump campaign's ties with Russia. In late April, Jacobs reported on Gianforte's substantial investments in US-sanctioned Russian companies, including Gazprom and Rosneft. Gianforte, through his spokesman, has said he did not oversee the details of his portfolio on a daily basis and Gianforte has pledged, if elected, to place his assets in a blind trust. Yet it's not hard to imagine that Gianforte was less than happy about this information being publicized.

Whatever happens to Gianforte's political career, however, his actions should be a wake-up call for the GOP: sooner or later, it will be time to clean house. And it's a message for all of us -- if we don't stand up to condemn the use of physical violence against the media, we all may become the targets of harm later on.