But the Border Patrol and ICE are defacto law enforcement agencies and they can do this already, so it is not more stringent than current Federal law.

So if they stop people to check for illegal handguns or drugs?

Questioning one's status at the border as that person attempts to enter the US is far different than questioning one's status on the streets of Phoenix, based solely on a cops reasonable suspicion and NOT being detained for questioning on another matter.

It's interesting that the DOJ suit that 'they' keep saying will be filed any second focuses not on 4th amendment or lawful contact issues, but on federal jurisdiction to set immigration policy.
I don't really get that, because the AZ law doesn't set new policy, it's just an attempt to enforce known public policy with state and local agencies.

On the other hand, we have California passing the Compassionate Use Act way back in '96 - that puts state law at direct odds with Federal.

From what I have read, the DoJ is considering challenges on both issues, but the supremacy clause issue would logically be the first test, being the more overriding of the two.

The timing....it is common practice NOT to file too far in advance, particularly if the fed and the state are privately attempting at some level to reach an agreement on modifications to the law.

But how does the supremacy issue make any sense here?
That would be like saying that state and local law agencies cannot enforce federal drug laws. But they do.

It is not saying that at all.

AZ law enforcement officials can and do enforce the federal immigration law, based on language in the federal law and an agreement between the feds and the state.

The AZ law goes beyond what that agreement allows under the federal law by criminalizing illegal immigration at the state level. The Supremacy Clause establishes that the federal law always prevails when federal/laws are in conflict.

Don't states have individual drug laws?

ie. Marijuana is a controlled substance under federal law, but penalties/enforcement for possession vary by state.

Possession of illegal drugs has never been solely a federal crime nor does federal law identify it as such.

What the AZ laws does is make illegal immigration a state crime when federal law (and the Constitution?) deems it to be solely a federal crime....that the states can help enforce, but NOT make more restrictive than the federal law.

ICE is all over the country, not just the border. The Border Patrol operates all over the country, but primarily at the border. I have seen Border Patrol Agents in Oklahoma City.

ICE agents are federal agents enforcing a federal law.

State Troopers seem to be the ultimate law enforcement agency at all state levels. It seems to me that they have great leeway to enforce all law, both state and federal. You keep saying the AZ law is more restrictive, when it is not. We have already agreed that Federal police agencies (ICE and Border Patrol) have the same authority that they are giving to local and state police agencies in AZ.

In the opinion of many, the AZ law is more restrictive because it create state arrest authority for violations of federal immigration law in situations that do not exist under federal law.

The issue is not state troopers being the ultimate law enforcement agency, but the state legislature and governor enacting a law that says illegal immigration is a state crime...when the Constitution (?) and federal law deem immigration legislation/regulation to be a federal matter...with enforcement support from the state.

Shortly after the U.S. Civil War, some states started to pass their own immigration laws, which prompted the U.S. Supreme Court to rule in 1875 that immigration was a federal responsibility[1].

Supreme Court case, Chy Lung v. Freeman.

Illegal immigration is a crime. ICE and Border Patrol arrest and detain persons who are here illegally everyday. The only difference I see is that now a state level or lower duely appointed law enforcement official can now assist the feds in doing the same, arresting and detaining persons for a violation of crime. They arrest people who can be tried under federal law on a daily basis, it just so happens that they are liable to arrest for similar violations at the state level. I don't see how that is more restrictive.