President Trump’s executive order is facing numerous court challenges, including a temporary restraining order.  My colleague David Bier has made a convincing statutoryargument that Trump’s temporarily ban on issuing visas to the nationals of Iran, Iraq, Syria, Saudi Arabia, Sudan, Libya, and Yemen is unlawful.  The genesis of Trump’s executive order was his campaign promise of a Muslim ban which, although unpopular, is built on a sturdier legal foundation than a 21st-century national origins quota.  If the court challenges fail and Trump’s ban is legal then there is a high probability that the bans will be extended and expanded to additional countries.  Indeed, section 2, subsections e and f of the executive leaves open the possibility of extending the length of such bans and extending them to additional countries.

The Trump administration will have to consider several points in order to place additional countries on the banned list.  The first is political.  Trump promised he was going to block countries that could send terrorists here after he called for a Muslim ban (that he later retracted).  He also seems committed to fulfilling his campaign promises through executive orders.  The other political consideration is avoiding the fierce criticism and mass protests that accompanied his first executive order.  Must of this opposition was based on the erroneous assumption that this executive order was a Muslim ban, although some opponents could be forgiven for thinking that.  To defuse the claim that his future actions will be a Muslim ban, Trump could include some non-Muslim countries on the banned list.  There are many non-Muslim countries in armed conflicts to choose from but I would place my bets on the swiftly disintegrating Venezuela.

The second consideration is the risk of terrorism from foreign nationals.  As I’ve written elsewhere, the risk of foreign-born terrorism on U.S. soil is small and even smaller for foreigners from certain countries.  The Trump administration could target some countries that send few immigrants and tourists to the U.S. but have historically sent many deadly terrorists.  The most likely candidates there are Egypt, Lebanon, Saudi Arabia, and the United Arab Emirates – countries where the 9/11 hijackers came from.  Foreign nationals from those countries received a total of 17,835 green cards in 2015, about a third as many as the foreign nationals banned in Trump’s original executive order.  Afghanistan, Kuwait, and Pakistan are also possible – the latter mainly because one of the Saudi terrorists was actually born in Pakistan although she lived almost her entire life in Saudi Arabia.  Afghanistan hasn’t sent any deadly terrorists but it is a scary place.

Altogether, foreign nationals from these additional seven Muslim countries and Venezuela were granted 54,260 green cards in 2015 – slightly more than nationals from the first list of seven nations banned in Trump’s original executive order.  Those nations all sent 1,344,337 non-immigrants to the United States, mostly tourists, in 2015.  That number is almost 16 times as great as the number who came from the banned countries on Trump’s original executive order.  The economic impact of a ban on these eight countries will be bigger than the original executive order.

Trump’s third consideration is foreign affairs.  The United States is allied with Iraq and has alliances with many of the other countries that could be subject to future visa bans.  Surely this must negatively affect America’s alliances just as the targeting of Japanese in the Immigration Act of 1924 caused a serious diplomatic row with that Empire.  The other foreign policy angle is how America’s adversaries view a ban.  After all, the U.S. immigration system was a source of anti-American propaganda for the Soviet Union and their Communist allies until the 1965 Act – passed partly in response to that international pressure during the Cold War.  Many commentators have already commented on how ISIS propaganda benefits tremendously from this ban.  Regardless, any extension or expansion of the migration ban will affect America’s foreign affairs, regardless of the wisdom of our existing alliances and policies, to such an extent that Trump must consider the effects.

A panel of judges in the 9^th Circuit this evening will hear arguments on Trump’s migration ban.  The legal issues surrounding Trump migration ban will not disappear anytime soon but if the ban is legal then this administration will have to consider the factors I outline above when it seeks to extend and expand the ban.