I am always very suspicious when politicians use the Bible to justify their actions.
The sole purpose of the Bible is to present God’s plan of salvation through Christ Jesus (John 3:16). This was the reason for St. Paul to write his Letter to the Roman Christians. In Romans 13:1 Saint Paul writes that Christians are to be submissive to government.
He wrote this to Roman Christians for civil order and he also wrote that we are to love our neighbor as ourselves and this is the fulfillment of the law (Romans 13:9-10). Peter and the other apostles said that, Christians are to obey God rather than men (Acts 5-29). Jesus said, My kingdom is not of this world (John18:36).
It is terrible misuse of scripture for the US Attorney General to justify the separation of parents and children at our southern boarders by quoting Saint Paul. It would seem to me that the only crime that these parents have committed is seeking protection for their families from violence in their countries.