A group of 14 Democratic lawmakers on Tuesday signed a letter that called for the release of Mahmoud Khalil, a Columbia University graduate who helped organize anti-Israel protests at the Ivy League college in Manhattan.

Khalil is a green card holder who was arrested Saturday by federal immigration authorities. He is also married to a U.S. citizen. He is currently being held by U.S. Immigration and Customs Enforcement (ICE) at a facility in Louisiana.

The letter comes after Secretary of State Marco Rubio said the U.S. will be revoking the visas and green cards of Hamas supporters in America.

“Mahmoud Khalil must be freed from DHS custody immediately. He is a political prisoner, wrongfully and unlawfully detained, who deserves to be at home in New York preparing for the birth of his first child,” the lawmakers wrote, per The Hill. “Universities throughout the country must protect their students from this vile assault on free thought and expression."

The letter also urged the Department of Homeland Security to stop arresting green card holders for expressing their views.  

“Khalil has not been allowed to see his counsel or his wife, and until the morning of March 10th his whereabouts were unknown," the letter reads. "DHS initially informed them he was being held in Elizabeth, New Jersey, but his wife attempted to visit the facility on Sunday only to learn that he was not there."

The 14 lawmakers who signed the letter are:

California Rep. Lateefah Simon

Georgia Rep. Nikema Williams

Illinois Rep. Delia Ramirez

Indiana Rep. Andre Carson

Massachusetts Rep. Ayanna Pressley

Massachusetts Rep. James McGovern

Michigan Rep.  Rashida Tlaib 

Minnesota Rep. Ilhan Omar

New York Rep. Nydia Velázquez

Pennsylvania Rep. Summer Lee 

Texas Rep. Al Green

Texas Rep. Jasmine Crockett

Wisconsin Rep. Gwen Moore

Wisconsin Rep. Mark Pocan

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.