some people did not know why they were kicked out. A few were told and it boils down to them being labeled a security risk. They need t o serve in the military to become full citizens, so this is barring them from that right in this "land of the free". There is even a possibility of sending them back to their country of origin, for no reason other than than whatever brand of "its not racism: you prefer.
https://www.nytimes.com/2018/07/05/us/charlottesville-plea-hate-crimes.html
Take a look at this, a fascist plead not guilty to hate crimes involving driving a car into a bunch of anti-fascist protesters, who arrived in response to a white nationalist rally. He is a racist, white nationalist, and is anti-semitic. Let me guess, for the hundredth time this year this fascist terrorist attack was just a result of mental illness (a card only played when the person is a white right-winger)