Here's something the Christianist right won't bring up in the immigration debate (although they often refer to it when it comes to marriage equality). Leviticus:

Leviticus 19:33-34 (NIV)

When an alien lives with you in your land, do not mistreat him. The alien living with you must be treated as one of your native-born. Love him as yourself, for you were aliens in Egypt.

A reader adds:

Also see:

Leviticus 19:33
Exodus 22:21
Exodus 23:9
Deuteronomy 24:17-18
Leviticus 19:9-10
Deuteronomy 24:19-22
Deuteronomy 10:18-19

Hebrews 13:2

I have to say I am very proud of my church in this instance. Human dignity matters.