Ahead of his party’s shellacking in the 2018 midterm elections, Republican President Donald Trump spent weeks warning his supporters that a caravan of Central American migrants headed for the U.S border constituted an “invasion.”

Trump’s favorite television channel was his most important ally in that effort. Prime-time Fox News programs used the words “invasion” or “invaders” to describe migrants and asylum-seekers more times in the 30 days leading up to the Nov. 6 election than they did during all of 2015, 2016 and 2017 combined.

I used transcripts to analyze the use of the terms “invasion” or “invaders” to refer to immigrants or asylum seekers on Fox News prime-time programming from Jan. 1, 2015, to Nov. 30, 2018. The analysis shows that, although the network was pushing anti-immigrant rhetoric before Trump announced his candidacy, a noticeable uptick occurred in the months around the 2018 midterm election. Prime-time Fox News hosts and guests used the words to refer to migrants 33 times in the 30 days ahead of the election, up from 25 times in all of 2015, 2016 and 2017. Fox has kept up the attacks in the weeks after the Republicans lost the U.S. House: Prime-time hosts and guests used the terms 48 times between Election Day and the end of November. Most of the mentions came from Fox hosts Laura Ingraham and Tucker Carlson.

Calling migrants “invaders” is a long-honored right-wing media rhetorical tradition. In 2002, far-right pundit Michelle Malkin ― who regularly appears on Fox News, often to attack immigrants and refugees ― published an anti-immigrant book called Invasion: How America Still Welcomes Terrorists, Criminals and Other Foreign Menaces to Our Shores. In 2015, Fox News used the term to spread anti-Muslim rhetoric in the context of the European refugee crisis. Ousted host and alleged serial sexual harasser Bill O’Reilly branded the humanitarian issue as a “Muslim invasion” in his Sept. 15 show that year. During an episode that aired about a month later, O’Reilly and his guest Monica Crowley focused on the “fighting age” or virility of those seeking asylum. Trump’s former top adviser, Breitbart executive Steve Bannon, was another fan of the idea; he often describes The Camp of the Saints, a racist 1970s French novel about a literal invasion of Europe by people from other continents, as a prophetic description about the present.

And Trump is far from the first Republican candidate to borrow from Fox News’ bigoted rhetoric for electoral gain. Fox News favorite Bobby Jindal attempted to run for president by regularly using the slogan “immigration without assimilation is invasion,” hammering on it throughout his short-lived candidacy.

The right-wing media noise machine has grown significantly since 2015, and the results of Trump and Fox’s symbiotic relationship clearly has the power of inspiring extremists. The right-wing echo chamber now includes anonymous message boards like 4chan and 8chan ― two video hosting platforms that amplified Alex Jones’ conspiracy theories by airing content from his site Infowars ― and social media networks like Gab, where extremists get further radicalized.

When I analyzed “politically incorrect” boards on anonymous forums 4chan and 8chan, I found that more than 2,200 posts referred to migrant caravans with the terms invasion or invaders. The trend showed an observable spike on Oct. 22, a day Trump tweeted repeatedly about the caravan.

The man behind the hate-fueled shooting on Oct. 27 in a Pittsburgh synagogue, for example, had posted six days before the shooting on the “haven for white nationalists” site Gab that he had “noticed a change” in the way people on the platforms referred to immigrants. “People saying ‘illegals’ … now say ’invaders,” he noted. “I like this,” he added. His last post before the shooting attacked HIAS, a Jewish nonprofit that helps refugees resettle in the U.S., for bringing in “invaders.”

Alex Jones repeatedly pushed the invasion narrative throughout October. Jones, whose extremist posts got him kicked off of multiple social media platforms, has previously bragged on air about his access to Trump’s White House.

And yet, President Trump and his right-wing media figures refuse to connect the dots between their rhetoric and the extremism it inspires or take responsibility for mainstreaming and empowering extremists.

White supremacist podcasts praise Tucker Carlson, for elevating their discourse into the mainstream. Yet Carlson denies having any influence on them.

Right-wing media and Trump have benefited immensely from incendiary rhetoric. They just don’t want to own the consequences.