The most intractable arguments tend to be those on which everyone has a good point.
Everyone gets to point at their point and ignore the other guy's. Perhaps "ignore" is too strong a word but can we agree that just about every point-of-view on immigration policy has at least some small measure of validity?
IS2M that the immigration brou-ha-ha is a tool for people with bigger agendas (winning at the ballot box and thereafter robbing the Treasury). Like abortion (...which Dr. Brin deconstructed pretty well a while back...), immigration is a perfect political issue for rousing the Faithful so long as it remains unresolved, which may explain why it has remained unresolved for so long.
I suggest we approach the subject de novo; all political factions have sinned, if all were punished according to our desserts who would yet stand?
The first question to ask is: What is the best immigration policy for America?
I suggest some priorities:
(A) maintain the Constitution
(B) maintain liberty
(C) maintain security
(D) maintain a healthy economy.
We can argue which oughta be ranked higher or even what some of those words *mean*, but if we accept the above ranking, the answers on immigration policy simplify.
As to LIBERTY: A "papers please" law mandating that you carry proof of citizenship or face a penalty, however mild, violates liberty completely. BUT proving that you have right-to-work in the USA at employment time is no additional infringement on liberty, since you have to submit tax information anyway to both state and federal bodies. (It's worth noting that Arizona's aggressive eVerify requirements has been accompanied by a large reduction in the number of illegals in that state.)
As to SECURITY: Any illegal traffic is a security threat because it establishes channels through which nastier payloads than an illegal drywaller can travel. However, it is simply not possible to seal our national borders physically and it is worse than silly theater to try; setting up barriers establishes laboratories for smugglers to experiment with (just think what Prohibition did for speedboat technology!) But a legalized, regulated trade in booze did, and in labor will, shut down the smuggling operations by simple applications of the laws of economics.
As to ECONOMY: the only reason you hire illegals is that they're cheaper than Americans, for reasons discussed ad nauseum. That undercuts wages paid to Americans and contributes to unemployment. (And it's not just in the farm sector; how can legitimate drywallers and roofers and meatcutters compete with illegal labor?) Why don't we figure out roughly how many immigrants we want here to supplement our citizen work force and issue that many work visas? And if you're caught paying an illegal, your fine is the entirety of the prevailing wage - meaning, you paid the market wage anyway, and whatever you paid the illegal was a gift.
IIRC there used to be a minority of conservatives who could talk rationally about immigration, e.g. John McCain, but in our current political climate, silly theater like Arizona's law and a border fence is too valuable for diverting attention away from serious discussion of serious solutions.