No one can reject migrants and refugees and say they are following the ethics of the Bible: 
"Do not deprive foreigners and orphans of their rights; and do not take a widow's garment as security for a loan. Remember that you were slaves in Egypt and that the Lord your God set you free"(Deuteronomy 24:17-18) 
"God's curse on anyone who deprives foreigners, orphans , and widows of their rights"(Deuteronomy 27:19) 
"Do not ill treat or oppress a foreigner; remember that you were foreigners in Egypt. Do not ill treat any widow or orphan. If you do I, the Lord, will answer them when they cry out to me for help, and I will be angry and kill you in war"(Exodus 22:21-24) 

Our Lord Jesus in his Parable of the Sheep and Goats(Matthew 25:31-45) list as one of the Works of Mercy how we treat the stranger. Furthermore his judgement isn't only on individuals, but on Nations as well.