If I remember by "Old Testament" God usually just told the Israelites to slay any outsiders in their lands, so actually Trump is being overly generous by only building a wall and kicking them out.
My first thought as well. When he gave the land to the Chosen People, God required that they slay everyone else, women, children and cattle, in order to establish (the original) Israel. Especially the Ammonites; in some chapters he scolded them for not having finished that job and letting the Ammonite king live.
As far as the "turn the other cheek" lesson from the gospels, it is a perfect lesson in interpersonal relationships, but does not necessarily apply to affairs of state or the things of Caesar. That job is outlined in Romans.