SAN FRANCISCO, CA (NBC) - Lawyers representing the state of Arizona are in a federal courtroom in California today appealing a ruling that struck down its controversial immigration law.
In July, a judge blocked portions of Arizona's new immigration law that required police to ask for immigration papers, let officers make warrantless stops of suspected illegal immigrants, and required immigrants to carry their papers.
But that didn't keep law enforcement from rounding up suspected undocumented immigrants.
The U.S. 9th Circuit Court of Appeals will hear from both sides: the State of Arizona and the federal government, which sued over the law.
Legal experts predict the Supreme Court will ultimately decide the boundaries of border laws.
Ten other states are currently weighing similar, tough immigration laws.
There are an estimated 12 million undocumented immigrants in the U.S.