On Friday afternoon President Trump signed a broad executive order suspending entry of all refugees to the United States, blocking entry of citizens from seven Muslim-majority nations for ninety days, and barring all Syrian refugees indefinitely. An unsurprising move considering candidate Trump’s promise to ban entry of all Muslims to the U.S., the executive order reverberated throughout the world in the first day after Trump’s signing.

By Saturday afternoon numerous reports had come in of refugees and citizens from the targeted countries being detained at airports, among them an MIT student and an Oscar-nominated Iranian Director who will have to miss the ceremonies. Protestors quickly assembled at JFK airport and other airports across the nation and remained there through the evening, holding signs that read “Legal Visas = Let Them In,” “Let my friends in,” “No ban, no wall”.

Responses from the international community were swift, with Iran moving to ban entry of all U.S. citizens and Canadian Prime Minister Justin Trudeau offering to take in refugees turned away as a result of Trump’s ban. British Prime Minister Theresa May, who was the first foreign leader to meet with President Trump, has been under pressure to condemn the executive order which would prevent Tory MP Nadhim Zahawi from entering the U.S., as well as Olympic gold medallist Sir Mo Farah. After declining to condemn the ban while in Turkey on Saturday, she issued a statement that night in which she said that she “does not agree with” the executive order.

Additionally, the legality of President Trump’s immigration ban has quickly come into question in light of Congress’ 1965 Immigration and Nationality Act, which prohibits discrimination against immigrants based on their “nationality, place of birth, or place of residence.” The Trump administration seems likely to invoke national security as an exception as the executive order references the terror attacks of 9/11, however candidate Trump’s comments calling for a “total and complete shutdown of Muslims entering the United States" as well as favoring admission to Christian refugees over Muslims might undermine their argument.

Late Saturday evening the first legal blow was dealt to the ban, with a federal judge granting emergency stay to citizens of the seven countries from which travel is now restricted who had already landed in the U.S. with a valid visa. The decision was on behalf of a suit filed by the ACLU early Saturday morning. The move frees travelers from the various nations who were already en route to the U.S. when the executive order was signed from the custody in which they had been placed.

It is largely unclear whether the immigration ban will survive in court, however it‘s not unlikely if the Trump administration can sufficiently make their case on the basis of national security. Meanwhile, the President said Saturday that “It’s working out very nicely”, maintaining that his executive order does not amount to a “Muslim ban”. Trump also ignored criticism that while it restricts travel from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen, the ban does not restrict travel from Saudi Arabia, the United Arab Emirates, Egypt, and Lebanon — the various countries of origin of the nineteen 9/11 hijackers.