Nor in Trump’s or IS’ own ignorance, although this too is demonstrable. More significant is the constituent ignorance that both Trump and IS rely on for their appeal. Ignorance is their shared heartland, their fertile ground, their enabling trait. In the marketplace of ignorance, hatred is a valuable commodity. There, schooling, sophistication and subtlety are the qualities to be feared. Seasoned America-watchers say Trump has run the most unashamedly racist campaign since George Wallace, the segregationist (Democrat) governor of Alabama who had four tilts at the presidency in the 1960s and '70s. Wallace, regarded as a moderate on race, coined the notorious promise: “segregation now, segregation tomorrow, and segregation forever” and presided over ‘Bloody Sunday’ in Selma, 1965. As Martin Luther King noted at the time, “nothing in the world is more dangerous than sincere ignorance and conscientious stupidity.”

Half a century on, Wallace’s daughter Peggy says Trump is, if anything, more extreme. Yet, astoundingly, he remains the Republican frontrunner, a success for which many credit his adept media manipulation, especially social media. (Trump tweets personally, complete with caps-lock and spelling errors. Cynics note that this is entirely strategised by 29-year-old Justin McConney, who has grown Trump’s Twitter following to 5.7 million. But still it lends Trump an air of authenticity that suits both his “real man” positioning and his demographic.) Yet there’s another, more sinister possibility. Perhaps Trump is popular not despite his relentless hate-peddling and Islamophobia, but because of them. Perhaps Trump’s cartoon conception of goodies and baddies is precisely what appeals. This is where ignorance matters. We’re familiar with IS’ faux-religious propaganda, but propaganda is also Trump’s weapon-of-choice, and propaganda always calls to ignorance. Dog-whistle politics needs biddable puppies. When Trump insists “we should have a lotta systems” to track all Muslims in America; when he answers the question “when can we get rid of Muslims?” by saying “we’re gonna be lookin’ at that and plenty of other things;” when he plays the “natural born” issue, or insists that Mexican immigrants are criminals, drug-traffickers and rapists, or that “thousands” of New Jersey-ites cheered the 9/11 attacks, or supports the attackers of a Black Lives Matter protester at one of his rallies, he plays deliberately to the un-nuanced world view of ignorance.

When he quips “I don’t like losers”; when he tells cheering audiences “the press are liars, they’re terrible people” or “politicians are weak and incompetent” or that he would “bomb the shit out of" IS, ring them with troops and send Exxon in to “take their oil” – when he says “I would do things that would be so tough I don’t know that they’d even be around to come to the table” – this, too, is propaganda. Yet Trump claims gold-class religious credentials. His own book is his second all-time favourite because, naturally, the Bible is top. “I have a very great relationship with God,” he told CNN. “I have a very great relationship with evangelicals.” He doesn’t ask God’s forgiveness, he explains, because he doesn’t need it. “I am good. I don’t do a lotta things that are bad.” There’s a dangerous chosen-people-ism here. The 2015 American Values survey (tellingly titled Anxiety, Nostalgia and Mistrust) showed that 62 per cent of Americans believe God gave America a special role in human history. The same survey showed that most US Christians think Islam is incompatible with American values, including 73 per cent of white evangelical Protestants, 63 per cent of white mainline Protestants and 55 per cent of black Protestants (compared with only 40 per cent of non-Christian Americans).

Similarly, 72 per cent of all white Christians (evangelicals, Protestants and Catholics) believe that police killings of African American men are isolated incidents, not part of some broader pattern. American Christians, it seems, are much happier to tolerate their own intolerance than other people’s. As theologian and activist Jim Wallis notes, “If white Christians acted more Christian than white, black parents would have less to fear for their children.” IS, of course, displays similar religious intolerance, with equally scant foundation and more extreme expression. Both religions, Islam and Christianity, have a fine tradition of reverence for education, yet both, now, seem in danger of relinquishing this in favour of a world ruled by fear, hatred, unreason and untruth. The appeal of Trump’s stark us-and-them-ism suggests a populace besieged by danger on all sides. In fact, says the Washington Post, the cross-border flow from Mexico has fallen by 75 per cent since 2000, much of that during the Obama years. At the same time, Muslim refugees “are often the very same civilians who face the indiscriminate violence and cruel injustice in lands controlled by the Islamic State in Iraq and Syria.”

Hating refugees as terrorists confounds all logic. IS is a genuine threat, of course, and sharia would be dreadful to live (or die) under. But IS wants the polarisation Trump delivers. Trump is their trojan horse. Indeed, their trump. Only education will undermine both. I don’t mean counter-propaganda, teaching Darwin in place of Creation. I mean genuine education in the skills of critical thinking. If privileged Americans (and Australians) could see beyond next week they’d cease hogging the best education for their own kids and positively force it on the underclass. Free, compulsory, high-quality education is not a matter of altruism. It’s a matter of survival, because civilisation demands both the freedom to let the village idiot speak, and the universal discernment to know, it is the village idiot speaking. Twitter: @emfarrelly