To add a footnote to Eric Claeys and Peter Schramms posts: The question here is how to get Davis out without getting Bustamante in. Conservatives have to win two votes, Davis one. Davis can win by campaiging against conservatives (hard) and against Bustamante (softly, e.g., signing the illegal alien driver license bill, which I think was a terrible mistake, politically, for him, as well as being despicable legislation to begin with).
In one view, McClintock may prove his irrelevance to the Republican Party in California by staying in and fading away to a distant third, behind the victorious Ahnold and Bustamante. Yet, his distance from the Ahnold campaign may be a boost to it as well: It makes less credible the likely last-minute assault by Davis of "right-wing coup" charges. If McClintock voters stay away from the polls altogether, that might help Davis on the all-important vote #1, getting him out.
If, and of course one mustnt anticipate victory, Ahnold and McClintock together poll more than 50% of the vote, it might signal the beginning of a governing majority in California that had a significant conservative presence. Building it in the legislature is a long-term project, made formidable by redistricting that freezes into place current Democratic majorities. Governing by plebiscite (initiative), where conservative issues can come to the fore without support of the "rotten boroughs" exacerbated by the weight of the illegal immigrant population, appears to be the only significant short-term answer. Ahnold could be a powerful presence in this strategy. Of course, first he needs to win.