As sharp as partisan political battles can be, nothing surpasses a full-blown shootout between members of the same party for sheer nastiness. Their ideological differences tend to be small and, therefore, their intraparty duels often turn personal. The increasingly shrill level of personal invective being thrown in the multi-candidate tussles for next year's presidential nominations of both parties illustrates the point. But in California, the syndrome is most evident in the overwhelmingly Democratic San Francisco Bay Area, which is renowned for sharp-elbow politics, and in Los Angeles. Bay Area voters may experience two nasty clashes next year as state Sen....