Students from other nations have also been a great source of intellectual energy and diversity at American universities. Relatively recent data published by the National Science Board (2012) document the continued rise in total foreign students in the United States–at both the undergraduate and graduate levels. “About 60 percent of all foreign graduate students in the United States in 2010 were enrolled in S&E [science and engineering] fields, compared with 32 percent at the undergraduate level.”

According to the Institute of International Education, in 2015-16, the largest number of foreign students came from China (about 330,000), India (165,918), and Saudi Arabia (roughly 61,000). There is widely considered to be a paucity of American students who study science and engineering. The foreign students who study in so-called STEM fields—some of whom remain in the United States after graduation—make up for this deficiency in the domestic educational system. China, for example, sends large numbers of graduate students to the U.S. for training and, as I wrote in my book, more than 80 percent remain in America country after they graduate, taking jobs in computer science,mathematics, and engineering. I was recently told by a colleague that at his university, foreign applications this year were down by around 15 percent. Were this source of talent to dry up or disappear, the nation could find itself with a deep deficit of talent to fill highly skilled jobs—to say nothing of the research departments at universities that focus on these subjects.

As one of his first acts in office, President Trump signed Executive Order 13769, “Protecting the Nation From Foreign Terrorist Entry Into the United States.” Washington state and Minnesota challenged this order almost immediately. Because the order was aimed at Muslims from seven countries, the states’ attorneys general claimed it violated the Establishment Clause of the U.S. Constitution and the Equal Protection Clause of the 14th Amendment. After the stay of the order by the U.S. District Court in Seattle, the case was heard by the 9th Circuit Court, which upheld the lower court’s decision. In order to meet the requirement of “standing,” the Circuit Court wrote: “The States argue that the Executive Order causes a concrete and particularized injury to their public universities, which the parties do not dispute are branches of the States under state law.” The intense scrutiny the executive order places on Muslim and others—even scholars from Europe who are being questioned at airports about their purpose for coming the United States—will have multiple negative consequences on the country’s universities.

Universities and colleges have become more international both by choice and necessity. Many of the nation’s great universities actively recruit students from around the world to increase the diversity of the college experience for all of its students. Moreover, at many of the finest public universities, where the states have reduced per-full-time-pupil spending by a median of more than 20 percent, foreign students are superb targets for seats: They often pay full tuition, which helps make up for the states’ budgetary strangulation of their flagship universities. But many of these scholars and students may soon begin to self-select out of a chance to come to the United States. More than 70 years ago, Robert Hutchins, then the president of the University of Chicago, observed that the problem with witch-hunts was “not how many professors have been fired for their beliefs, but how many think they might be.” If the United States becomes less appealing to scholars from abroad, they may well stay home, depriving America of their talent. Fear and uncertainty have become the order of the day. Executive orders or legislation that represses immigrant groups often, historically, morph into laws against American citizens. None of this bodes well for those interested in studying, teaching, or conducting research at American universities.

Beyond the particulars, America was once considered a compassionate and welcoming nation—opening its arms to those yearning to breathe free. The social and economic consequences of the imminent changes in immigration policy only expose the country’s dark side—one that we that, regretfully, could hurt the nation’s economy, pace of discovery, and the social fabric.

This article is part of our Next America: Higher Education project, which is supported by grants from the Bill & Melinda Gates Foundation and Lumina Foundation.

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