A federal judge sharply questioned the Justice Department's key argument that Arizona's immigration law interferes with federal enforcement of immigration law.
"Why can't Arizona be as inhospitable as they wish to people who have entered or remained in the United States?" U.S. Judge Susan Bolton asked in Thursday's hearing, according to the Washington Post.
She also questioned the argument that federal law "pre-empts" (i.e. trumps) the Arizona statute.
"Where is the pre-emption if everybody who is arrested for some crime has their immigration status checked?"
But Bolton also suggested that making it a state crime to lack immigration documents could violate a Supreme Court ruling prohibiting states from creating their own "immigration registration systems," the Los Angeles Times reports.
The Justice Department is asking Bolton to bar the law from going into effect next week.