A frightening “hate crimes” trial in Canada offers Americans a look at the future of the First Amendment if Muslim immigration to this country continues unabated. Conservative writer Mark Steyn, it seems, “offended” the Muslims in British Columbia, and now not only the Muslims but also the Canadian diversity police want their pound of flesh.

Steyn’s ongoing legal battle began in 2006, when Macleans magazine published an excerpt of his book, “America Alone.” The excerpt, “The Future Belongs To Islam” said nothing that anyone who reads the newspapers doesn’t know: Islam is conquering Europe. But it was “offensive” because it stated exactly that.

Europe, Mr. Steyn wrote, is dying. The Christian faith is waning. Birth rates have collapsed. His reasonable conclusion is that the growing and angry Islamic horde in Europe is preparing the ground for violence, and, indeed, jihad: Aging Europeans, he wrote,  are “being supplanted remorselessly by a young Muslim demographic. … [A]t the very minimum, this fast-moving demographic transformation provides a huge comfort zone for the jihad to move around in.”

Thus did the Canadian Islamic Congress sharpen its legal scimitars and haul Steyn and Macleans before British Columbia’s human rights commission, a Stalinist kangaroo court that stops normal Canadians from expressing opinions the radical left does not like. The Islamic group has made all manner of preposterous demands to salve its phony wounds, and Steyn wants to lose so he can appeal in a real court and expose this despotic lunacy for what it is.

But the particulars of Mr. Steyn’s case are not as important as the speech laws, prevalent across the Western world, which inspired it. In Canada, speech laws ensnared Mark Steyn; in France, Brigitte Bardot. Given that U.S. Supreme Court justices suggest that American courts consider international law in making decisions, the future does not bode well for the First Amendment. If such laws were passed here, a First Amendment court challenge against them might fail. Oddly, our paladins of the press don’t seem to recognize the danger. And we have our own ad hoc thought and speech police: campus leftists who so frequently shout down and even assault speakers with whom they disagree.

So Americans had better candidly address immigration from Muslim countries and what it means for American culture as well as the laws and political liberties that grew from an explicitly Christian moral order and understanding of human liberty. In Europe, the demographic impact of immigration is alarming: Politicians and clerics alike now suggest that codified Islamic law may well be the wave of the future. Canada may not far behind. What happens here when those same demographics, in Dearborn, Mich., for instance, coalesce with the zeitgeist of enforced “diversity” and ideological conformity to criminalize “hate” speech and silence journalists?

As a Muslim cleric told a Norwegian newspaper, then quoted by Mr. Steyn: “[T]he number of Muslims is expanding like mosquitoes. Every Western woman in the EU [European Union] is producing an average of 1.4 children. Every Muslim woman in the same countries is producing 3.5 children. … Our way of thinking will prove more powerful than yours.”

This, of course, is proving true. The question Americans must ask, given such centers of Islam as Dearborn, Mich., is what such a statement means for this country.