The Trump administration is justifying its efforts to deport a student at Columbia University by saying that his activities could “potentially undermine” the Middle East peace process. In a memo from the secretary of state, Marco Rubio, reviewed exclusively by the New York Times, the administration asserts that Mohsen Mahdawi, 34, a green-card holder and student who led pro-Palestinian protests at Columbia, had undermined the Middle East peace process and threatened the US goal to “peacefully” resolve conflict in Israel and Gaza. Mahdawi was apprehended at an immigration services center in Vermont, where he had arrived to complete the final...