Today (April 25) the U.S. Supreme Court heard oral arguments about the constitutionality of the controversial Arizona immigration control law (S.B. 1070). S.B. 1070 was passed in 2010 to help reduce the number of undocumented immigrants arriving (and remaining) in Arizona.
Since its inception, civil rights groups have challenged the law, focusing on the racial profiling aspect. However, the Supreme Court is not hearing arguments on this issue.
Instead, the Supreme Court is hearing oral arguments about the constitutionality of the law and whether it conflicts with federal law and/or disrupts federal enforcement.
Additional reading: NPR