DETROIT – States have the authority to enforce immigration laws and protect their borders, Michigan Attorney General Mike Cox said Wednesday in a legal brief on behalf of nine states supporting Arizona’s immigration law.

Cox, one of five Republicans running for Michigan governor, said Michigan is the lead state backing Arizona in federal court and is joined by Alabama, Florida, Nebraska, Pennsylvania, South Carolina, South Dakota, Texas and Virginia, as well as the Northern Mariana Islands.

The Arizona law, set to take effect July 29, directs officers to question people about their immigration status during the enforcement of other laws such as traffic stops and if there’s a reasonable suspicion they’re in the U.S. illegally.

President Barack Obama’s administration recently filed suit in federal court to block it, arguing immigration is a federal issue. The law’s backers say Congress isn’t doing anything meaningful about illegal immigration, so it’s the state’s duty to step up.

“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.

Arizona’s Republican Gov. Jan Brewer, in a statement released by Cox’s office, said she was thankful for the support.

In a telephone interview, Cox said the nine states supporting Arizona represents “a lot of states,” considering it was only Monday that he asked other state attorneys general to join him. The brief was filed in U.S. District Court in Arizona on the same day as the deadline for such filings.

“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,” the brief states.

The brief doesn’t represent the first time Cox has clashed with the Obama administration. Earlier this year, he joined with more than a dozen other attorneys general to file a lawsuit challenging the constitutionality of federal health care changes signed into law by the Democratic president.

Like with his stance on health care, the immigration brief again puts Cox at odds with Democratic Michigan Gov. Jennifer Granholm. Granholm, who can’t seek re-election because of term limits, disagrees with the Arizona law, her press secretary Liz Boyd said. The Michigan primary is less than three weeks away on Aug. 3.

“It’s a patently political ploy in his quest for the Republican nomination for governor,” Boyd said.