That LITERALLY happened to my friends coming back from Vietnam.
It also happened to a girl I knew in Air Force ROTC at Cornell in 1981
In 1980 I was in a bar with my recruiter when a couple came up to us and wanted to apologize for what they did in the 1960s to veterans and they said they spit on soldiers returning from Vietnam and called us Baby Killers
They told us they actually had classes in college ( not curriculum but organized by Anti war protestors) on how to harass servicemen
You can believe the lies you've been told in your fantasy land if you like but don't tell me what happened. I was there
Entering the country illegally is an administrative issue.So they get due process by being deported
By the executive branch who controls the administrative functions of the government