Freed Columbia University protester Mohsen Mahdawi was allowed to stride across the graduation stage Monday — just three weeks after being cut loose from an immigration jail. The 34-year-old, who was draped in a keffiyeh,

Draped in a keffiyeh, Mahdawi, 34, paused to listen to the swell of cheers from his fellow graduates. Then he joined a vigil just outside Columbia’s gates, raising a photograph of his classmate Mahmoud Khalil, who remains in federal custody.