Today is the time for all Americans of good will, who wish to keep their credentials as respectable members of society, to renounce Donald Trump, all his works, and all his empty promises.

Well, we’re not going to do it. Yes, we disagree with his off-the-cuff statements about cutting off all immigration for Muslims. We think that on this issue as on many others, Trump’s priorities are right, but he lacks the patience to work out effective policies — unlike, for example, his main competitor for hard-core conservative votes, Sen. Ted Cruz, who carefully sweats the details.

But first let’s talk about sentiments. Trump knows in his gut what the great Harvard scholar Samuel Huntington elaborated and proved: that our country was not designed to be operated without a tolerant Anglo-Protestant culture. Yes, Catholicism contains within it the materials necessary for nurturing a free society and indeed played a central role in the rise of freedom during the European Middle Ages and Renaissance. And yes, there were Catholics, such as Charles Carroll and semi-deists such as Thomas Jefferson, among the American founders, men who contributed mightily to the American Experiment. But we can acknowledge all that and also acknowledge that most politically incorrect of elephants in the room — namely that the American Experiment was largely English and Protestant, and that to pretend that either ingredient is incidental to its success is nothing short of willful blindness.

That culture is the vital lubricant that allows our Constitution to function, and if you replace it with something else, the whole magnificent Rube Goldberg is doomed to break down and explode. It doesn’t mean American Protestantism was immaculately conceived supporting religious freedom. Various Protestants pursued religious persecution against Catholics, Jews and other Protestants with great zeal until the influence of certain minority branches of Protestantism combined with a pragmatic need for the colonies to put aside religious differences and unite against the tyranny of the crown. Only then did religious toleration became a prominent feature of Anglo-American Protestantism. So, yes, it didn’t happen in a moment, but it did happen, and it happened in a group of colonies that were largely English and Protestant.

People from different countries and religious heritages can and have joined and contributed to the American Experiment, but doing so involves accepting the political creed of our Anglo-Protestant founders, who cleaved to individual freedom (including religious freedom), elected government, the rule of law and the sanctity of contracts. American Catholics had to answer tough questions in the past, given our church’s unhappy history on the religious freedom issue, but we proved ourselves over centuries. It was U.S. bishops who pushed hardest at Vatican II for the church to embrace religious liberty for all — as it did 60 years ago this week. The number of religiously motivated Catholic (or Orthodox, or Jewish) terrorists in American history is zero.

Our founders never envisioned the mass influx of devout believers in Islam, a religion that, unlike Christianity, is intrinsically ideological, offering a totalizing description of how societies should be run and vigorously denying that there should ever be a separation between church and state. The Quran combines with an authoritative tradition of detailed, specific decisions (hadith) to form a comprehensive legal code — sharia, which is meant to apply to every human being on earth. And very large percentages of modern-day Muslims accept straightforward readings of their holy texts insisting that every non-Muslim alive is a rebel against Allah deserving of the death penalty, and that the duty of every Muslim is to engage in jihad until the whole world is Muslim, or subject to Muslim supremacy, with tolerated non-believers cringing as third-class citizens and paying a punitive tax.

What we just described isn’t “radical Islam,” “Islamism,” “jihadism” or some peculiarity of ISIS. It is a mainstream and widely held understanding of Islam. The ones who reject such a vision for society are considered bad Muslims. The good Muslims, according to many mainstream Muslim clerics, embrace it. Consider the Muslim “Vatican,” Saudi Arabia, and its laws. They are indistinguishable from ISIS’s. The goal of any serious Sunni Muslim is to make the world one enormous Saudi Arabia.

So, how many Muslims of that sort do we really want in America? The ideal number is zero. As Mark Krikorian observed:

Islam’s non-religious element — sharia — “involves the organization of the state, comprehensive regulation of economic and social life, rules of military engagement, and imposition of a draconian criminal code.” That program of Islamic supremacism is fundamentally incompatible with the Constitution, and we should strive to minimize the number of people living in our country who hold such beliefs.

Our country’s foolish immigration policies, which Ted Kennedy designed to favor large clans of Irishmen flooding into Boston and registering as Democrats, in fact helped large number of good Muslims enter as well, and now they are citizens. This was a mistake, but we can’t reverse it without betraying our Anglo-Protestant culture of tolerance and tearing ourselves to pieces. We must preserve the rights of every one of these citizens as scrupulously as we would those of Baptists, Hindus, Jews or Catholics. We do so for our own sake, not out of respect for their supremacist religion.

When Franklin Delano Roosevelt interned peaceful Japanese-Americans in camps during World War II, he profaned our most sacred tradition, because he saw our survival at stake. We don’t want to repeat his mistake, and when Donald Trump suggests otherwise, he plays into the wringing hands of the unpatriotic Left, who really do seem to believe that the Constitution is a suicide pact.

Given the aggression and intolerance that are Islam’s unmeltable core, a certain percentage of even moderate Muslims coming of age in America will “get religion” and favor sharia and Islamic supremacy. As we learned in San Bernardino and in Paris, out of that number some will be willing to join the high-tech, worldwide conspiracy of Muslim terrorist violence, and murder the rest of us by the dozens. Given that fact, there is no reason to import more Muslims into our country, if we can avoid it without sacrificing our Anglo-Protestant tradition of religious liberty.

But is that possible? If we strive to keep out members of one religious group, aren’t we violating the First Amendment to our own Constitution? Strictly speaking, no. As Andrew McCarthy wrote at National Review:

Let’s bear in mind that permitting immigration is a discretionary national act. There is no right to immigrate to the United States, and the United States has no obligation to accept immigrants from any country, including Muslim-majority countries. We could lawfully cut off all immigration, period, if we wanted to. Plus, it has always been a basic tenet of legal immigration to promote fidelity to the Constitution and assimilation into American society — principles to which classical sharia is antithetical.

Perhaps it’s too legalistic to stop at that. Wouldn’t we be violating the spirit of the First Amendment, and introducing an era of inter-religious conflict into our country by adopting such a policy? The answer is no on both counts. If we can distill a “spirit” from the First Amendment, it’s that the government shouldn’t be monkeying with the religion of its citizens, period. The “free exercise of religion” does not apply in advance to foreign residents, nor include “filling up your empty pews with imported believers, whatever the impact on the rest of the country.” As for inter-religious conflict, it is already upon us, and good Muslims are the aggressors. Refusing to defend ourselves is not a Christian duty, but simply a sign of squeamishness.

We can slow the escalation of such conflict by reducing the flow of potential future enemy combatants flowing into our country. To do less is to neglect our children’s safety, and even their freedom. If America suffers 10 or 20 San Bernardino-style attacks every year, it will be impossible to fight off the drive for massive surveillance of every citizen’s email and phone accounts and incessant liberal attempts to confiscate our weapons.

It is no doubt too provocative to enact by statute a flat ban on Muslim immigrants, as Trump suggested. Instead, we should undertake practical, politically saleable reforms that have virtually the same impact, while leaving room for lax Muslims, ex-Muslims and Christian refugees from Middle Eastern countries. Mark Krikorian suggests that we revive the “ideological” exclusion that once kept out Nazis and Communists, and demand that potential immigrants accept the First Amendment — which means renouncing sharia. He also proposes

eliminating the visa lottery, an absurd program in its own right but also the source of a disproportionate share of Muslim immigration; limiting family immigration to the closest relations, to prevent a cascading chain of relatives; dramatically curbing refugee resettlement, allowing us to help many more people while keeping the potential security threats off shore; and reducing the number of foreign-student admissions, the feeder program for a large share of new permanent immigration from the Islamic world.

That all makes sense. We could soften the hysteria of “diversity” addled moderates by promising to admit Middle Easterners who could show that they were the victims of religious persecution — including ex-Muslims who might be subject to the death penalty for apostasy. We could increase foreign aid to Muslim civilians displaced by civil wars such as Syria’s. We could stop interfering in the internal politics of Muslim countries in attempts to democratize their governments, as we did in Iraq, Syria, Egypt, and Libya. Such efforts seem only to help the most radical Muslims, and increase both the death toll and the oppression of those who dissent from sharia.

We can practice both justice and mercy in our attitude toward Muslims. We must stand up for the real Constitutional rights of Muslim citizens to hold to their religion, and make sure that their mosques aren’t singled out for invasive government scrutiny, absent real intelligence that a given institution is fostering terrorism. We can empathize with those who are born into a faith that is incompatible with freedom, and pray for their conversion. But we must protect our citizens and our fragile public order, and doing that means rejecting sharia as exactly what it is: an alien, totalitarian ideology that has no place on our peaceful shores.