Mahmoud Khalil, a Palestinian activist who helped lead Columbia University's student encampment protests, has been arrested by ICE.

"This is the first arrest of many to come," the president said of Mahmoud Khalil, a green card holder abducted by immigration agents and sent to Louisiana.

Mahmoud Khalil's attorneys are challenging his arrest, which raises questions about First Amendment protections for non-citizen protesters.

Nearly 100 arrests were made at Trump Tower in Midtown after hundreds of Jewish New Yorkers and friends packed into the lobby to protest the arrest and detainment of Columbia graduate Mahmoud Khalil.Video taken Thursday afternoon showed officers handcuffing some of the demonstrators associated with Jewish Voice for Peace -- an organization that is critical of many of Israel's policies regarding Palestinians.