To overcome his better-funded rivals, Campbell is counting on the power of the Web as a fund-raising tool as well as the dynamics of a three-person race.
"A three-way race is exceptionally more achievable," Campbell said.
"I have precedent for that. It is somewhat ironic. It is Gray Davis beating Al Checchi and Jane Harman in 1998," Campbell said, referring to the former governor's Democratic primary win against a wealthy businessman and member of Congress who had injected millions into their own races.
A California Republican strategist not working for any of the 2010 candidates summed up Campbell's chances, saying, "He doesn't have a great shot because he doesn't have the money, but he doesn't have no shot.
"The conventional wisdom is that the California Republican primary electorate is dominated by right-wing activists but it's not," said the GOP strategist who asked that his name not be used. "No one likes the tax increases but the price for it is you finally get a spending cap.
"Poizner is already on the attack against Whitman. It's going to be very negative," the strategist added. "Campbell can potentially get up the middle."
ABC News' Ferdous Al-Faruque contributed to this report.