Trump administration planning illegal immigrant arrests throughout US on ‘day one’

What are they going to do, send him to jail?

You are lying. If there is no application to enter the country, it's legal to put them in jail only for that, and then put them on an internatioanl flight for one way travel. Of the government flies them inti the country but no application with approval showing their status within the country, the personal is an illegal alien. No person can be an illegal immigrant.