Under what circumstances can a US green card be revoked? [Courtesy] The recent arrest of Palestinian activist and U.S. legal permanent resident Mahmoud Khalil, who played a prominent role in last year’s Columbia University protests over the war in Gaza, has prompted questions about the limits of a green card. A green card holder since 2024, Khalil was granted lawful permanent residency status in the U.S. But green card holders can lose their status and face deportation if they violate immigration law. A federal judge on Wednesday extended efforts to halt Khalil’s deportation, and the New York resident remains in…