I think conservatives, when discussing the new Arizona immigration enforcement law, have largely dealt with the issue strictly in relation to the fact that illegal immigration, especially in Arizona is a huge problem and is starting to get American's killed. All of this is true.
However, Dean Esmay makes an important point:
For the record, I don’t have a problem with a state deciding to enforce immigration laws. If they want to do that, that’s fine by me. But let’s call this what it is: a massive increase in government power that will affect the lives of ordinary citizens. If it’s necessary then it’s necessary, but either way it’s what we’re talking about here.
I don't know how Dean characterizes his own politics, but I know he's a good deal to the left of me and most people who would characterize themselves as conservatives. (I remember him supporting the health care bill, for instance). Yet, here he is making the limited government argument, and it's a very good point.
Does Arizona have a pressing need to enforce immigration? I think that they likely do. Let's be honest, however, This is an expansion of government intrusion into people's lives and that intrusion will cover more than just the illegal immigrants it's intended to catch.