Facing a deadline from an immigration judge to turn over evidence for its attempted deportation of Columbia University activist Mahmoud Khalil, the federal government has instead submitted a brief memo, signed by the secretary of state, Marco Rubio, citing the Trump administration’s authority to expel noncitizens whose presence in the country damages US foreign policy interests. The two-page memo, which was obtained by the Associated Press, does not allege any criminal conduct by Khalil, a legal permanent US resident and graduate student who served as spokesperson for campus activists last year during large demonstrations against Israel’s treatment of Palestinians and...