"I'm running for governor for a very simple reason; I love California," Riordan told the crowd at a huge rally on Olvera Street, where the city was born more than a century ago. The newly announced candidate, who served two terms as mayor of this city before being forced out by term limits earlier this year, chided Davis for what he believes is the governor's failure to make good on several campaign promises. These include Davis' pledge to improve public schools and health-care while also reigning in state spending.

Riordan, 71, is considered by most pollsters to have the best shot at beating Davis and reclaiming the governor's office for the GOP. He is a moderate Republican who supports both gun control and abortion rights, which sets him apart from the two other major Republican challengers—Secretary of State Bill Jones and conservative LA businessman William Simon.

A Field Poll released last month, before Riordan announced that he would run, showed the former mayor in a virtual dead heat with incumbent Davis and far ahead of both Jones and Simon. As mayor, Riordan was praised for his efforts to help rebuild LA after the 1994 Northridge earthquake and for making the city more "business friendly," but was criticized for failing to initiate major changes in the scandal-ridden Police Department.