Gov. Jan Brewer voiced support for an Arizona congressman's bill to allow states to require citizenship documents from all people registering to vote.

The Arizona Republic reported that Brewer sent a letter this week to Republican Rep. Matt Salmon in support of his bill, a response to a U.S. Supreme Court ruling.

The high court's ruling said Arizona can require proof of citizenship from people registering to vote only when they're using state registration forms. The ruling said the documents can't be required when people use a federal registration form.

Brewer said it's the responsibility of state and local governments to protect the voting process, and that she backs efforts by Salmon to ensure that only citizens are voting.

The bill awaits a hearing in Congress.