Donald Trump wins again. Oh, he's still not going to be president. His new offensive -- coming out for a "total and complete shutdown" of Muslim immigration and travel to the U.S. -- won't get him any closer to taking over the White House. But he has once again succeeded in taking over the news cycle.
Attention that could have gone to whether President Barack Obama's strategy to destroy Islamic State has any chance of success is instead going to Trump's latest half-baked idea. Actually, that gives it credit for too much time in the oven. Trump's plan would work on the honor system, apparently: We'd ask travelers if they're Muslim and turn away those who say yes.
But as unserious as the proposal is, it's worth thinking through what's wrong with it, if only to clarify the continued relevance of our tradition of religious toleration in the age of terrorism.
Republicans and Democrats have been arguing recently over how to fight terrorists who claim to act in the name of Islam without making all Muslims into enemies. Most Republicans say that we should distinguish between "radical Islamic terrorists" and Muslims who believe in peace and tolerance. Hillary Clinton avoids that phrase and talks about "radical jihadists" instead. Trump takes a different view altogether: We should make hostility to Muslims the official policy of the U.S. government.
The world's 1.6 billion Muslims would get the message loud and clear. We'd be broadcasting that we consider them all our enemies and want them to stay away, that we dislike and fear them more than we cherish our professed ideals of religious tolerance. Muslims living in the U.S. -- some of them citizens, some of them soldiers and veterans -- would get the same message. (Yes, even though Trump said that he loved "the Muslims" three months ago. All is flux in the mind of Donald Trump.)
Other Republican presidential candidates have talked about showing a preference for Christian rather than Muslim refugees from the Middle East. Up to a point, a preference is defensible. Christians in the region are often fleeing severe religious persecution, and our existing procedures may disproportionately leave them behind. We might therefore need to make special efforts to help them. But that's different from a blanket ban on Muslims -- including people who need protection from persecution for being the wrong kind of Muslims.
Trump is citing a bogus poll to justify his proposal. But there's no doubt a lot of Americans have anxieties about Muslim immigration -- and these anxieties don't always reflect simple bigotry. One set of anxieties is based on concerns about terrorism.
Though the vast majority of Muslim immigrants and travelers to the U.S. are peaceful, there's no denying they're more likely to join a jihadi cell than Buddhist visitors are. But perfect safety from terrorism, as from crime, isn't possible; a ban on Muslim travelers wouldn't do much to make us safer, and it would undermine both our ideals and our foreign-policy objectives.
Other worries concern Muslims' integration into our free society. Many Muslims don't believe in religious liberty, for example. In the 19th century, nativists directed such fears at Catholic immigrants. Although these worries were mixed with bigotry, they weren't baseless: The Catholic Church really was hostile to freedom of religion. Yet Catholic immigration to the U.S. didn't end up subverting American liberalism so much as it liberalized Catholicism. It had this effect because Americans lived out their commitment to toleration. A ban on Catholic immigrants would've been an enormous mistake, denying us the talents of tens of millions of people and retarding the spread of our principles.
That's part of how America became a great nation. Our next president, who won't be Trump, should strive to keep us so.
Ramesh Ponnuru, a Bloomberg View columnist, is a senior editor for National Review and a visiting fellow at the American Enterprise Institute.