Frankly to me, you sound like one of the Pharisees.
I don't have one at hand, because I came across the references while skimming - but it is interesting to see how much Bush sounds today as he did during his 2000 campaign in regards immigration.
What would Jesus do? Well, God's Word is very clear as to that answer and what Christians should do. According to Romans chapter 13 we are to OBEY the laws of the land and submit to governmental authorities. Seeing that Jesus will one day rule the earth with a rod of iron I hardly think he is going to put up with lawlessness of any kind.
People entering the country illegally; stealing or falsifying identification in order to get work or working under the table are ALL breaking the law. Were you or I to do what they are doing in another country, we would be arrested immediately and deported or incarcerated because we would be criminals. As for Revelation 7:9-10, you are sorely mistaken in your misapplication of the text. Having taught the book on the graduate and undergraduate level I can assure you that the multitude of believers from every nation, tribe and tongue who will be saved during the period of the tribulation as a direct result of the 144, 000 Jewish witnesses has absolutely nothing to do with foreign nationals entering the United States illegally and committing fraud or worse in order to live and work here. The first rule I teach my students in Hermeneutics is context and the context of Revelation 7 in now way shape or form supports your premise.
Lastly, this has nothing to do with legalism and everything to do with obeying the laws of the land and prosecuting to the fullest extent of the God given law, those who willfully have chosen to break it by entering the country illegally.