Erickson, a Georgia native, backed Handel against a crowded GOP primary field.
Handel has shown momentum in recent weeks, picking up an endorsement from former Alaska Gov. Sarah Palin (R) and capitalizing on one of her opponents' gaffes for positive media coverage. She has far less money than some of her rivals, but seems to be faring well ahead of the May 20 primary.
Erickson's endorsement could help her with the ideological base in the state. He said he'd been debating between Handel and Rep. Paul Broun (R-Ga.) in the endorsement process.
Polls show a tight five-way race, though most have found Rep. Jack Kingston (R-Ga.) and businessman David Perdue (R) ahead of Handel, Broun and Rep. Phil Gingrey (R-Ga.).