Even more ridiculous and blinkered is the suggestion that there may be something unconstitutional about refusing entry to refugees or discriminating among them on religious or other bases (a reaction that was shared at first by some Republicans, including Mike Pence, when Trump’s plan was announced in December 2015). There are plenty of moral and political arguments on these points, but foreigners have no right under our Constitution to demand entry to the United States or to challenge any reason we might have to refuse them entry, even blatant religious discrimination. Under Article I, Section 8 of the Constitution, Congress’s powers in this area are plenary, and the president’s powers are as broad as the Congress chooses to give him. If liberals are baffled as to why even the invocation of the historically problematic “America First” slogan by Trump is popular with almost two-thirds of the American public, they should look no further than people arguing that foreigners should be treated by the law as if they were American citizens with all the rights and protections we give Americans.

Liberals are likewise on both unwise and unpopular ground in sneering at the idea that there might be an increased risk of radical Islamist terrorism resulting from large numbers of Muslims entering the country as refugees or asylees. There have been many such cases in Europe, ranging from terrorists (as in the Brussels attack) posing as refugees to the infiltration of radicals and the radicalization of new entrants. The 9/11 plotters, several of whom overstayed their visas in the U.S. after immigrating from the Middle East to Germany, are part of that picture as well. Here in the U.S., we have had a number of terror attacks carried out by foreign-born Muslims or their children. The Tsarnaev brothers who carried out the Boston Marathon bombing were children of asylees; the Times Square bomber was a Pakistani immigrant; the underwear bomber was from Nigeria; the San Bernardino shooter was the son of Pakistani immigrants; the Chattanooga shooter was from Kuwait; the Fort Hood shooter was the son of Palestinian immigrants. All of this takes place against the backdrop of a global movement of radical Islamist terrorism that kills tens of thousands of people a year in terrorist attacks and injures or kidnaps tens of thousands more.

There are plenty of reasons not to indict the entire innocent Muslim population, including those who come as refugees or asylees seeking to escape tyranny and radicalism, for the actions of a comparatively small percentage of radicals. But efforts to salami-slice the problem into something that looks like a minor or improbable outlier, or to compare this to past waves of immigrants, are an insult to the intelligence of the public. The tradeoffs from a more open-borders posture are real, and the reasons for wanting our screening process to be a demanding one are serious.