Under the law, known as SB 4-C, anyone who “knowingly enters or attempts to enter [Florida] after entering the United States by eluding or avoiding examination or inspection by immigration officers” can be convicted of a first degree misdemeanor.

Florida's Attorney General James Uthmeier, a Republican, and other state officials filed the emergency request on June 17 asking the Supreme Court to halt the judge's order. Williams found that the Florida law was likely unconstitutional for encroaching on the federal government's exclusive authority over U.S. immigration policy.

The law, enacted this year, made it a crime for unauthorized migrants to enter the state. Challengers say immigration is a federal matter.