Here is Michigan Attorney General Bill Schuette's take on the U.S. Supreme Court's ruling on the Arizona illegal-immigration law that was challenged by the Obama Administration:
“I’m pleased the Court upheld some authority of states to exercise a role in border enforcement. However, it’s disappointing the ruling did not uphold the broader authority of state governments to enforce laws intended to ensure the safety of their citizens. I will be reviewing the opinion thoroughly to determine its impact on the State of Michigan.” 
Schuette says in a press release the nation’s highest court upheld the provision of Arizona’s law (SB 1070) permitting law enforcement to make a “reasonable attempt,” “when practicable” to ascertain the immigration status of any person lawfully stopped, detained or arrested “where reasonable suspicion exists that the person is an alien and unlawfully present in the United States.
Schuette noted Justice Samuel Alito’s opinion on the Court’s decision to uphold this section (§2(B)):
That provision does not authorize or require Arizona law enforcement officers to do anything they are not already allowed to do under existing law.  The United States’ argument that §2(B) is pre-empted, not by any federal statute or regulation, but simply by the Executive’s current enforcement policy is an astounding assertion of federal executive power that the Court rightly rejects.  -(Opinion of Alito, J, p. 2).
Michigan served as the lead state on the amicus brief filed in support of Arizona by state attorneys general with the U.S. Supreme Court, Schuette says. Schuette challenged Obama Administration arguments that states could only enforce federal law if the federal government granted them specific permission to do so. The state coalition argued in favor of the states’ authority to enforce federal immigration laws, especially in light of the selective and even lack of enforcement of those laws by the Obama administration, Schuette says.
States that joined Michigan include: Alabama, Florida, Georgia, Idaho, Indiana, Kansas, Louisiana, Nebraska, Oklahoma, Pennsylvania, South Carolina, South Dakota, Virginia, West Virginia, and Wyoming