Must voters have to prove citizenship to register?

WASHINGTON (AP) — The Supreme Court will hear arguments today about validity of Arizona's voter registration law. It tries to keep illegal immigrants from voting by demanding that all residents show documents proving their U.S. citizenship before registering to vote in a national election.

Four other states — Alabama, Georgia, Kansas and Tennessee — have similar voter registration requirements, and officials say another 12 states are considering such legislation.

The Obama administration is supporting challengers to the law, who argue that if Arizona can add voter registration requirements that go beyond the federal form, they and other states can ask for things like age, residency, mental competence and felony history.

A federal appeals court threw out the part of Arizona's Proposition 200 that added extra citizenship requirements for voter registration, but only after lower federal judges had approved it.

Arizona wants the justices to reinstate the requirement.