In December, Donald Trump famously called for a temporary ban on all non-citizen Muslims entering the United States until our politicians “can figure out what the hell is going on.” This proposal immediately accrued the condemnation of all the other Republican Presidential candidates and most of the GOP establishment while simultaneously provoking outrage from virtually everyone on the left. Both President Obama in the State of the Union Address and Governor Nikki Haley in the Republican response to it made unambiguous, if not explicit, criticisms of the proposal. Say what you will about Trump’s bombast and boorishness, there is an intuitive genius behind anyone who can engender essentially universal scorn from opinion professionals across the political spectrum by offering a proposal which nevertheless, according to Rasmussen, wins the approval of 66% of likely Republican voters and (46%-40%) of all voters to boot.

Opponents of Trump’s proposed ban, including President Obama, argue that: (a) it would not be consistent with our “values” or our Constitution, (b) it would be playing right into ISIS’ hands by driving hapless, moderate Muslims into their radical waiting arms and (c) it would be impractical and easily evaded by actual Islamic terrorists anyway.

I wish to argue here that the instincts of the ordinary voters who agree with Trump are fundamentally sound – that it is Islam that is often disturbingly inconsistent with our values, that failing to stand up for those values is pusillanimous and will ultimately work to our detriment and that maybe a clever business guy might develop a plan whereby, with the right balance of incentives, the United States could drive a wedge between ISIS and the peaceful segment of the Islamic world.

Americans’ suspicion of Islam goes far beyond the fear of a small, radical minority murdering our citizens. There is a longer term concern that both at home and abroad a populous Muslim culture exists that is stubbornly incompatible with liberal ideals. Polls consistently show that overwhelming majorities of Middle Eastern Muslims support the death penalty for apostasy, blasphemy and homosexuality and the view that Sharia law supersedes all other human law. They show that anti-Semitic beliefs are registered in large majorities of Islam and that while open support for ISIS is only in the high single digits in most Middle Eastern countries, still, for example, 62% in Pakistan, refuse to give an unfavorable opinion.

There is no constitutional requirement that we must admit anyone to America, much less those who subscribe to pernicious ideologies. The so-called “plenary power doctrine” and a hundred years of Supreme Court precedent have upheld the view that due process for aliens is whatever Congress says it is. Nor does it make sense that the Constitution be viewed as an ethical Kantian imperative or Mosaic code that applies to all humans, not just Americans. Aliens coming to your country are like visitors coming to your house. No one expects to be castigated for their choice of guests.

So suppose that President Trump did in fact institute a ban on all Muslims coming to America. How would it work? That depends on what: “until our government can figure out what is going on” means. This rather vague qualifier could simply mean, for example, “until a review of the visa application process is carried out.”

But suppose it meant instead a more far-reaching quid pro quo. It is hardly unreasonable to expect adherents to a faith that sanctions the murder of cartoonists in foreign lands to demonstrate that they do not abide by such principles. One obvious way to do that would be to require a Muslim applicant for a visa to the United States to obtain a signed document in English and Arabic – call it a “liberal Islam” affidavit – from the Imam of the mosque where the visa applicant worships, attesting that that Imam does not preach (for example) death to all apostates, nor that Jews and homosexuals are inferior beings nor that Sharia law supersedes secular law in foreign lands – specifically in America.

Undeniably, actual terrorists might either forge such a document or else lie about being Muslim. And instituting programs administered from the embassies in the various Islamic countries that tabulate mosques and the teachings of their Imams – and whether they have signed a liberal Islam document – would admittedly be a difficult and costly bureaucratic undertaking. But one of the major problems with radical Islam is finding clerical authorities in the Middle East who will go on the record with regard to, for example, the sanctioning of the murder of heretical cartoonists. Such a program would force the religious establishment to choose and provide significant incentive for choosing right.

Consider the following. Roughly 100,000 visitors arrive in the U.S. from the Middle East each month (a fifth of these are from Saudi Arabia) and the purpose of much of this travel is business-related. An edict requiring individual mosques to at least ostensibly recognize Western principles would immediately require serious accommodation from religious authorities if only for financial purposes.

One of the brilliant points of Trump’s plan is that it recognizes implicitly that America, and the privilege to visit her, is a highly valuable commodity. The vast majority of Muslims are, we are told, peaceful people. Perhaps we can use this American commodity to pressure the religious leaders of those peaceful people into recognizing the liberal values of tolerance and co-existence on which the success of our civilization is founded.