2) Compassionate social conservatives like Bush, and my twp GOP committeeman St Rep Paul Froehlich support relaxed immigration for the same resons they are pro-life. Included in this are many of us citizens who have family/friends who are illegals, eg my inlaws. (My previously illegal wife is now closer to a Rosanna type Mexican than I am.) Both #1 and #2 include strains of abolitionist Republicans who see little difference between slaves and illegals in terms of morality.
3) Mercantilists are those evil corporations who seek that expanded supply of labor for their own gain.
4) Finger-to-the-wind moderates are afraid they will be called racist. Look at how often Minutemen are called racist. I disagree with them. But the ones from Illinois whom I know are not racist
5) Roveites see an opportunity to capture a voting bloc that is conservative on social issues, is pro-family with a strong work ethic and has the lowest rate of application for welfare of those qualified to apply of any ethnic group. Since Paul Froehlich and I have had local success at obtaining the votes of Hispanics, we may have mixed reasons for our position... except that I think the cause and effect on that are the reverse. In my 7 precincts I obtained 100% of the Hispanic vote for Bush (with 1 exception) and for Paul Froehlich in 2001 because I seemed friendly to Hispanics, which I probably am. My suburb is changing from White Trash to Hispanic. I do extremely poorly among divorced people and promiscuous women, which are a large part of the prior demographic.
Your inlaws are illegals?
You outline one of my problems with libertarians. And I am one , sort of. You dont want something to be illegal so you condone it and excuse it, hoping that the momentum caused by the non-enforcement that you helped create in the first place makes some prohibition unrealistic instead of working to change law. That bugs the hell out of me.