I don't quite understand what is all the fuss over immigration. Everybody who evolved here from a worm, stand up and raise your hand. Anybody? Ahhh, exactly as I thought. We're all immigrants here. How can anyone possibly espouse a policy of anti-immigration? If they think immigration is bad, they have a very simple course of action: LEAVE!. "America: love its immigration policy or leave it."
In particular, conservative opposition to unrestricted immigration makes no sense to me. You hear conservatives say "When guns are outlawed, only outlaws will have guns." They understand the principle there very well. Then they complain that immigrants commit more crimes than average. Well, how about this:
"When immigration is outlawed, only criminals will immigrate."