They're not citizens but they were willing to put their lives on the line for the U.S. And an estimated 3,000 U.S. veterans are either in deportation proceedings or being detained.
Jorge Rivas at Fusion has the story:
Hector Barajas joined the 82nd Airborne in 1995, he served as a paratrooper, jumping out of planes dozens of times and taking on various missions on behalf of his country. But in 2004, after being honorably discharged, the United States put him on a flight that led to his biggest battle: being deported to Mexico, a country he left before his fourth birthday.
Barajas, who had a green card, returned to California after his discharge. A month later he began having trouble with the law. He pled guilty to firing a weapon at a car that his friend believed was following them. No one was wounded and Barajas maintains he didn't pull the trigger.
Had Barajas been a U.S. citizen, he would have served three years in a state prison and that would have been the end of it. But because he wasn't, he was deported to Mexico a year later. He was doubly punished[.]
And Barajas is not alone. Read about the issue at Fusion.