Kerwin Swint is a Professor of Political Science at Kennesaw State University . He wrote a book in 2006 called Mudslingers: The Top 25 Negative Political Campaigns of All Time.
California has two campaigns that make the list but the last one was in 1950.
This is an excellent book for political junkies. Some of these tactics that were used by these candidates even decades ago are pretty outrageous.
In California I actually see more hard hitting races in Democrat primaries. They seem to have no problem going for the jugular early on.
On the Republican side we have a couple races coming up in 2008 that could certainly make the list and at least one in 2010 that has great possibility.
In Mudslingers the races that rose to the top of the list usually involved race and accusations of extra martial affairs.