When President Trump issued an executive order late Friday suspending the immigration of refugees and people from seven predominantly Muslim countries, the order was quickly traced back to his advisers Steve Bannon, the former publisher of Breitbart News, and Stephen Miller, a former aide to now-attorney general nominee Jeff Sessions.

The astonishingly cruel and incompetently executed order reflected a view of Muslims, and particularly of Muslim refugees, that Bannon frequently promoted at Breitbart. As the head of the conservative outlet, he regularly lifted up the voices of leading anti-Muslim extremists and used his daily Sirius radio program to share a dystopian vision of what he depicted as western civilization overrun by a Muslim “invasion.”

Bannon seemed especially taken with the description of refugees offered in the 1975 novel “The Camp of Saints” by French author Jean Raspail. Raspail’s dystopian vision of dark-skinned refugees taking over a white Europe has become popular among American white supremacists. Bannon cited the book at least twice on his radio program; once was in an interview with Sessions, where he warned that the “Muslim invasion of Europe” is “almost a Camp of Saints type invasion.”

While Trump spent his campaign demonizing refugees, calling them the “ultimate Trojan horse” and vowing to deport Syrian refugees already in the country, it appears to be Bannon and Miller who shaped that rhetoric into policy.

It’s this mindset that informed Trump’s executive order—and that will likely have another powerful voice if Sessions is confirmed as attorney general. In a story calling Sessions the “intellectual godfather” of Trump’s executive actions on immigration, the Washington Post’s Phillip Rucker and Robert Costa lay out the close alliance and ideological affinity between Sessions, Bannon and Miller when it comes to immigration issues: