Published: Jun 12, 2012 12:15 PM EDT

TUCSON, Ariz. (AP) - Voters in Virginia, Maine, Nevada, North Dakota and South Carolina are going to the polls for primary elections today -- but one of the most closely-watched races is in Arizona, where voters are choosing a successor to congresswoman Gabrielle Giffords.
She has made few public appearances since she was seriously wounded in a shooting attack that left six people dead. But she has returned to Tucson in recent days to help the former director of her district office, Ron Barber, who is running against Republican Jesse Kelly.
Giffords resigned in January to focus on her recovery.