If the 9th Court says so

In a huge win for Russell Pearce and other supporters of Arizona's Employer Sanctions Law, the Ninth U.S. Circuit Court of Appeals upheld the law. This will no doubt encourage those states sitting on the fence to move forward with their own versions as many other states have already done so. Rep. Pearce noted that it's unlikely it will be appealed to the U.S. Supreme Court since that would definitely make it a national precedent.

In the appeal, it was noted that future lawsuits would not be controlled by this ruling meaning that if an when an employer is prosecuted, they could appeal and have their case heard.

It should be noted that the Ninth Circuit Court is considered a liberal court so if they are upholding it, you can bet it's pretty air tight.