It's an anti-incumbent vote, with the public at large knowing very little about any of the Republican candidates.
Based on that, it is hard to tell how the race will turn out yet. A Republican running for statewide office in California generally cannot win on anti-incumbent sentiment alone.
Campbell has what it takes to win, imo, but it's going to be that much harder to beat a democrat in a federal race, rather than a statewide race. He would have had a much easier time becoming governor. Whitman is a worse candidate than him and even she has a good chance of becoming governor, and depending on how Brown runs, she might even be the favorite.
Campbell sounds too intellectual to win, from what I've heard from debates and speeches. I don't see how he could appeal to Latinos. I have no idea how many lower income whites who are culturally conservative and uneducated but still vote for Democrats still exist in California but I could see Campbell underperforming in areas that contain these voters.
Wrong. Campbell effectively backflips around the entire Boxer strategy. California is a fiscally moderate and socially liberal state. Campbell is a fiscal moderate and social liberal. Campbell supports abortion rights, gay marriage, environmental protections, and firearm restrictions. Boxer does, too, but this is a large bloc of Bay Area and SoCal voters, middle to upper-middle class suburbanites who want fiscal responsibility, modern government, and social liberalism. With social issues effectively cancelled out, the campaign will be fought over economic issues. As a former finance director and Dean of Economics at UC Berkeley, Campbell is in a strong position. He also has shown himself to be a budget hawk and at the same time, able to raise taxes when necessary. There is no way for boxer to pigeonhole tom Campbell as she has other opponents. Tom Campbell can win these Bay Area moderates and SoCal suburbanites that the Democrats rely on to build their big majorities. Tom Campbell, yes, will run weaker among Hispanics (though Meg Whitman will do very well with them), but he will get enough Hispanics that he still has a net gain after making ground among suburban voters. If Tom Campbell wins, he will win 50-47 over Barbara boxer in a close fought and very expensive contest. No other candidate has this potential.