Nine states have officially backed Arizona's new immigration law.
Michigan Attorney General Mike Cox said the Wolverine State is the lead state backing the law, and has filed a supporting brief in federal court on behalf of Alabama, Florida, Nebraska, Pennsylvania, South Carolina, South Dakota, Texas and Virginia.
"Arizona, Michigan and every other state have the authority to enforce immigration laws, and it is appalling to see President Obama use taxpayer dollars to stop a state's efforts to protect its own borders," Cox said in a statement.
The Obama administration recently filed suit to block the Arizona law and argues immigration is a federal issue. The states have countered that they're authorized to enforce immigration laws and protect their borders.
"By lawsuit, rather than by legislation, the federal government seeks to negate this preexisting power of the states to verify a person's immigration status and similarly seeks to reject the assistance that the states can lawfully provide to the Federal government," Cox wrote in his brief.
The Arizona law requires officers to question people about their immigration status during enforcement of other laws if they suspect they're in the U.S. illegally. The law goes into effect July 29.