DeVore also predicted a backlash by conservative voters against Campbell's support for Proposition 1A, a failed ballot measure last year that would have temporarily raised taxes by $16 billion in return for something many Republicans sought -- stricter limits on state spending.

The National Organization for Marriage launched a nearly $300,000 ad campaign this week to rip Campbell on both the tax and same-sex marriage issues, said DeVore, predicting that the campaign will hurt the former congressman, state finance director and dean of UC Berkeley's Haas School of Business.

"You find conservatives supporting Campbell -- and that can't last, it won't last," DeVore said.

"As conservatives figure out that it's Tom Campbell who wants to raise your taxes, then what I think will happen is that for every three (percentage points of support) he'll lose, I'll probably get two, Fiorina will get one. The question will be: Will it be enough?"

Jamie Fisfis, Campbell's spokesman, dismissed DeVore's prediction as "delusions of grandeur."

"How would he get two points out of three if no one knows who he is?" Fisfis asked.

Proposition 1A had both a temporary tax element and a spending cap, so if DeVore wants to criticize Campbell for supporting a tax increase, then DeVore should accept blame for opposing a spending cap, Fisfis said.

"We're not really concerned that our support would fall to DeVore levels," Fisfis added.

DeVore also took aim at Fiorina, former chief executive officer of Hewlett-Packard.

The third-term lawmaker did not back down when asked about his characterizing Fiorina as a "self-funded dilettante" last year.

Asked how he would define "dilettante," DeVore said: "Somebody who has, in this case, parachuted into politics using money and business connections to make up for what people like Tom Campbell and myself have done through a lifetime of activism and public service."

DeVore criticized Fiorina for spotty attendance on an advisory board and spotty voting in state elections.

"That, to me, is indicative of someone who's a dilettante, someone who's not serious about public service," he said.

Fiorina spokeswoman Julie Soderlund said later in an e-mail that the candidate's team had been trying to determine what DeVore's campaign strategy is, "and now we know: name calling."

"His comments also seem to rest on the notion that only political insiders should be running for office," Soderlund said.

"Carly is the only candidate in this race who comes from the real world, not the halls of Sacramento or Washington," she added. "We're happy to run on that record any day."

This post was updated at 5:12 p.m. with comments from Fiorina spokeswoman Julie Soderlund.

PHOTO CREDIT: U.S. Senate candidate, Assemblyman Chuck Devore, R-Irvine, talks with the Bee Capitol Bureau on Wednesday. Randall Benton/rbenton@sacbee.com