In a January press conference, California Attorney General Xavier Becerra dodged questions about specific provisions of the new Immigrant Worker Protection Act, AB 450, saying that his department was working on “guidance” for employers wishing to avoid huge fines for voluntarily complying with requests from federal immigration officers. Tuesday (nearly a month later) he held a press conference with Asm. David Chiu, author of AB 450, to present a seven-page document detailing how the state intends to enforce the law.

If you’re not familiar with AB 450, it prohibits private and public businesses of all sizes from voluntarily cooperating with immigration enforcement officers, from allowing said officers from entering “nonpublic” areas of the business, and requires that employers notify employees who’ve been identified by federal officials as possibly having deficiencies in their I-9 documentation (giving them a chance to flee).

Despite the Act’s name, Becerra said, “Let me stress again, AB 450 is about privacy, constitutional rights and Californians at the workplace.”

Unfortunately, the “guidance” doesn’t provide much of it because so many of the terms are undefined or poorly defined. Never fear, the legal beagle told employers wary of possibly violating federal law in order to be in compliance with state law: “There is no conflict with what AB 450 requires and what federal laws require.”

The federal government begs to differ. ICE spokeswoman Lori Haley told USA Today:

“[The Immigrant Worker Protection Act] reflects yet another effort by the State of California to interfere with federal immigration enforcement authorities. Federal law established by the Immigration Reform and Control Act (IRCA) of 1986 requires employers to verify the identity and work eligibility of all individuals they hire.”

In addition to the “Do I follow federal or state law” dilemma employers face, the definitions provided in the guidance produce more questions than answers. For example, the guidance notes that the statute does not define what a “nonpublic area” is, and states it “should be given…its usual or ordinary meaning. A “nonpublic” area is one that the general public is not normally free to enter or access.”

After noting that an employer’s definition of what is public or nonpublic is not controlling, the document states:

It is important to recognize that every place of employment is different and whether or not a business premise, or any part thereof, constitutes a “nonpublic” area of a place of labor is a factual, case-by-case determination that will depend on an assessment of all the circumstances in any given situation.”

Which means that it’s completely subjective and depends on whether they want to fine you or not.

Becerra and Gov. Jerry Brown continue to maintain that California has the autonomy to create its own policies on the matter. But no less than Kamala Harris (then California’s Attorney General) argued against state-based immigration policies just a few years ago in a brief filed supporting the federal government’s position in Arizona v. United States:

California told the court that any state interference with federal policies of removal is strictly unconstitutional as an interference with federal priorities and policies. The brief insisted that “removal’s inherently national character extends to enforcement activities in aid of removal, such as arrest and detention and “such enforcement inevitably targets foreign nationals” and rests solely with the federal government.

Indeed, California argued that a “patchwork of separate removal policies would undermine ‘the nation’s need to ‘speak with one voice’ in immigration matters.’” Thus, California argued that the Court should not allow a state to “interfere with the achievement of the federal priorities that Congress has set” and Arizona should be blocked on the ground that its law “conflicts with Congress’s national removal policy.”

Fortunately for those who believe in the supremacy clause and the rule of law, the document Becerra produced today just provided a lot of ammunition.