The point is that immigration policy involves a conscious choice: do we want to let this person into our country and society or don't we? Every country will have its own homegrown eccentrics, wackjobs, weirdos, geeks, sluts, bloods, wastoids, dweebies, dickheads - they all adore him. They think he's a righteous dude. Sorry, got carried away. The point is that they've been part of the national consciousness for centuries. With new immigration, there are legitimate questions to be asked about integration (which by necessity includes accepting the existence of Calvinist extremists).

The issues around Muslim immigration are really three separate issues that often get conflated and muddled around. First and foremost is the real and legitimate fear of terrorism, generally of the Salafist flavor. Added to this is the general level of intolerance that many in Muslim societies have for people who aren't like them (notably Jews, gays and secularists but also women, particularly emancipated women, Christians and others), which often finds its expression in repressive practices that run the gamut from the simply abhorrent (forced hijab) to the criminal (honor killings). Finally, there is the generalized sense of the "other" that any immigrant group has to get over in a new society, which is not at all unique to Muslims but which still exists.

It's clear that every society keeps out the terrorists, and every society allows some people in despite a generalized anxiety about the "other" that many have. It's the second issue that leads to the most controversy because people differ in their opinions about where to draw the line. I personally would err on the side of caution - let in no one who frequents any Salafist mosque for any reason, let in no one who believes in killing for apostasy, or being gay, or who espouses anti-Semitic beliefs (yes, I realize Arabs are technically Semites, but we all know anti-Semitic means anti-Jewish). Let in no one who would seek to chastise someone for eating pork, or drinking, or wearing short skirts. Let in no one who would ever consider arranging their children's marriages rather than letting those children choose. Let in no one who has no desire to learn the language or fails to do so in a reasonable amount of time. Multiculturalism is wrong thinking. Not all cultures express the same level of tolerance to ours that we do to theirs.