* Requiring a check of the immigration status of anyone stopped by police.
"For any lawful contact made by a law enforcement official or agency of this state or a county, city, town or other political subdivision of this state where reasonable suspicion exists that the person is an alien who is unlawfully present in the United States, a reasonable attempt shall be made, when practicable, to determine the immigration status of that person," is what the law says.
* The law makes it a crime to be in Arizona if you are in the United States illegally. The offense is a misdemeanor, unless the person is found to have illegal drugs, materials to make methamphetamines, a deadly weapon or items that could be used to commit terrorist acts.
* The third section in dispute is section 5(C) of the law which prohibits any illegal immigrants from working in Arizona or even from applying for a job in the state.
"It is unlawful for a person who is unlawfully present in the United States and who is an unauthorized alien to knowingly apply for work, solicity work in a public place or perform work as an employee or independent contractor in this state."
* Section 6 allows officers to arrest people - without a warrant - if that officer has "probable cause to believe" that the individual "has committed any public offense that makes the person removable from the United States."
The Ninth Circuit Court of Appeals held that this part of the Arizona law "significantly expands the circumstances in which Congress has allowed state and local officers to arrest immigrants," ruling that it "interferes with the carefully calibrated scheme of immigration enforcement has adopted."
For critics of the federal government, that's the problem, that there really is not a "carefully calibrated scheme" when it comes to stopping and then deporting illegal immigrants in the U.S.
This is how the Justices laid out the case when cert was granted in December of 2011:
"Arizona enacted the Support Our Law Enforcement and Safe Neighborhoods Act (S.B. 1070) to address the illegal immigration crisis in the State. The four provisions of S.B. 1070 enjoined by the courts below authorize and direct state law-enforcement officers to cooperate and communicate with federal officials regarding the enforcement of federal immigration law and impose penalties under state law for non-compliance with federal immigration requirements.
"The question presented is whether the federal immigration laws preclude Arizona's efforts at cooperative law enforcement and impliedly preempt these four provisions of S.B. 1070 on their face."
One person that will be missing from these arguments is the newest Justice, Elena Kagan. She recused herself from the Arizona case because she had worked on the matter while serving as Solicitor General previously in the Obama Administration.
Obama Health Law Arguments Rematch
Making this case even more interesting is that the major players in the Obama health law case are back before the High Court to duel again over immigration.
Arguing for the Obama Administration will be Solicitor General Donald Verrelli, who became a household name after an underwhelming second day of arguments on the constitutiality of the individual mandate.
Making the case for Arizona will be former Bush Administration Solicitor General Paul Clement, who was in charge of the arguments for the states that were challenging the Obama health reforms.
Just as those arguments were a spirited legal - and political - discussion, many expect this case may have the same electricity.
That was certainly shown in a Senate hearing on Tuesday, as the chief author of SB 1070 tangled with two Democratic Senators before the Senate Judiciary Committee over the constitutionality of the law.
As one might expect, the two sides came to much different conclusions.