SAN FRANCISCO -- The three Republicans vying for the chance to unseat Sen. Barbara Boxer (D-Calif.) this fall were tripping over themselves yesterday in a rush to capitalize on momentum generated by a rare special-election upset in a liberal stronghold 3,000 miles away.

Separate statements from the campaigns -- from former Rep. Tom Campbell, Assemblyman Chuck DeVore and former Hewlett Packard CEO Carly Fiorina -- had managed within hours to form a three-part swipe at Boxer, the chairwoman of the Senate Environment and Public Works Committee. Their message was this: Barbara Boxer, you're next.

DeVore's version was typical. "This is not the first time the Bay State has started a revolution," he said. "Now it's up to us to continue what began in Massachusetts, and return common-sense conservative and constitutional principles to the center of American governance."

Campbell attacked "Barbara Boxer's reckless abuse of our tax money," while Fiorina, the candidate who recently transferred $2.5 million of her own money into her campaign's checking account, pledged to "hold [Boxer] accountable for her failed record."

California Republican Party Chairman Ron Nehring summed up the jubilant mood in GOP circles with his own statement. "Barbara Boxer can't be too happy with [the] results," he said. "If Massachusetts can elect a Republican to the United States Senate in 2010, so can California."

To Republicans, the result in Massachusetts, in which state Sen. Scott Brown bested Attorney General Martha Coakley, was more good news after a month of bad poll numbers for Boxer and the Obama administration. Just last week, a Rasmussen Reports poll gave Boxer no more than 46 percent of the vote in a two-way matchup, with Fiorina netting 43 percent, Campbell 42 percent and DeVore, a relative unknown, 40 percent.

Those numbers represent Boxer's worst poll performance over the past year against the likely opposition in November. The poll also mirrors a slide for national Democrats. In a Field Poll released yesterday, President Obama's favorability rating in California was reported to have dropped over the last year, from 65 percent several months into his presidency to 56 percent this week (E&ENews PM, Jan. 20).

All of which had Boxer playing defense during interviews with reporters yesterday on Capitol Hill, where she was swamped with questions about her re-election.

"Everyone of my races has been really, really hard," Boxer said. "It's all the same for me. I run very, very hard."

Boxer and Coakley: No comparison

To the California crowd of analysts watching the Senate from afar, the upset in Massachusetts will likely prove to be a shot of adrenaline for an incumbent senator who is viewed favorably by a majority of the state but still vulnerable to the kind populist movement in evidence throughout the country.

While the result does speak to an atmosphere in which Boxer could lose, these analysts note that the Marin County resident is a seasoned political veteran who has survived tough statewide races. In other words, Boxer is no Martha Coakley, who has been criticized for running a lackluster campaign against Brown.

"For Boxer, the good news is that it only makes her more vigilant than she already is," said Max Neiman, a senior fellow at the Public Policy Institute of California. "Unlike Coakley, Boxer always 'runs scared.' She is a very strong campaigner."

"I'd be cautious about over-interpreting the Massachusetts Senate results," added Richard Feinberg, a political scientist at University of California, San Diego. "The flashier, better campaigner won. Whatever you may think about Barbara Boxer, boring she is not."

And Boxer has been raising money by the millions. Her campaign has a $7 million war chest on hand, which far surpasses the $5 million she had in the bank at this point in her 2004 re-election fight. To Gary Jacobson, also a professor of political science at UCSD, Boxer's financial position is a strength, but he wonders if she will have to distance herself from the White House in the months ahead, especially if the state's unemployment numbers -- currently at 12 percent -- continue to rise.

"I don't think any Democrat can rest easy this year, Boxer included," Jacobson said.

Boxer also has 10 months until Election Day, and she is running in California, which has more far more registered Democrats than Republicans but fewer independents than Massachusetts.

"There are some very big differences between Massachusetts and California," Neiman said. "There are many more Californians who would benefit from the public health option, whereas in Massachusetts, they already have universal health care for the state, which created a whole other set of potential issues for residents of that state. Moreover, there is a huge Latino population in California, with whom Boxer resonates very well."

Ripple effect, straight to the GOP primary

In the short term, a more immediate effect from Massachusetts is likely to be felt in the California GOP primary, which takes place in early June.

Brown's victory, and the Tea Party movement generally, would seem to benefit a candidate like DeVore, who is the conservative on the ticket running against two moderates. If DeVore manages to win the GOP nomination, analysts said, it will be because moderates split their vote between Campbell and Fiorina.

This would seem to favor Boxer in the general election, where conservatives have a hard time finding cross-over appeal. Indeed, many political experts in the state say Gov. Arnold Schwarzenegger (R), a pro-choice moderate who won in a recall election, would never have secured the GOP nomination in a primary fight.

"In the past, Boxer has been lucky in her opposition," said Jacobson, arguing that the California Republican Party has shifted to the right, especially as Obama's policies have taken hold. "DeVore strikes me as right there keeping up that tradition of weak opponents."

Shaun Bowler, a professor at University of California, Riverside, agreed that DeVore could have the inside track. If that takes place, he said, it favors Boxer.

"It will be a good primary season for conservative GOP because they can point to this series of GOP wins and say, 'Look, it shows we were right,'" Bowler said. "So, at this point a guess might be a drop in Boxer's vote share but still winning against a conservative Republican."

So that means Boxer's fate could be tied into how conservative the GOP base leans this summer. Another factor is Campbell, who recently switched his candidacy from the gubernatorial race to running for the Senate. If Campbell were to drop out before the primary, Fiorina -- who says she is pro-life and is doing everything she can to appeal to the right -- has a better chance, Carrick said.

"Campbell has a capacity to be a spoiler but not much more," said Carrick, adding that much will also depend on what kind of candidate DeVore turns into on the campaign trail. "He's kind of clever, he's got a good knack for getting publicity, and he's definitely going to be a pain in the you-know-what. But can he turn that into something bigger?"

DeVore, a proponent of reviving offshore drilling in California, has yet to prove he can raise the kind of money Boxer has raised or Fiorina can summon from her own bank account. But experts believe he might be helped by the Tea Party movement, which claims a quarter of its members live in California. (The party did not return calls seeking comment.)

"In a Republican primary in California, unless he's pretty incompetent, he should win," Jacobson said. "It remains to be seen what kind of candidate he is."

GOP chief responds

Nehring, the chairman of the California Republican Party, dismissed the importance of conservative ideology in the Boxer race. He said voters in Massachusetts voted less on Brown's apparent right-leaning philosophy than they did on a candidate that appealed to their sense of who might "translate vision into reality."

In California, he argued, this fall's election will likewise be less about philosophy than it is about Boxer's record and national issues like the economy and health care. He said if the race is about candidates and Boxer's record, it could play out much the same way it did in Massachusetts.

"This election will be fought in large part about whether they want more of the same Barbara Boxer, or whether they want an alternative," Nehring said. "If voters only made decisions based solely on a philosophical plane, then Martha Coakley should be packing her bags and heading to Washington right now."

As for Boxer's fundraising advantage, Nehring said money should be less of a factor for this "top of the ticket" race. He said Boxer has had six years to amass her war chest, and the GOP candidates should be able to catch up.

"At the end of the day, the Republican nominee will be as well known as Barbara Boxer," Nehring said.

Senior reporter Darren Samuelsohn contributed from Washington.