The Republican Party in Ventura County is split into two factions which have a long history of deeply disliking each other (and that's putting it very gently). There is no love lost between Gallegly and McClintock.
Tony Strickland is of course on Tom McClintock's side in these internecine battles (since Tony was a former staffer for Tom). Keith Richman, who represents the other Assembly district which is included in Tom's State Senate district, is a moderate-to-liberal Republican and falls in the other camp.
Richman will be termed-out in 2006, which gives him a little more time than Tony to find a new position. He's already run for mayor of the San Fernando Valley (and won), but since the overall succession vote failed it didn't mean anything. He can't go onto the State Senate as long as Tom is in the way. So he's been looking at running for a statewide office. Running for governor would give him some name recognition in preparation for a future statewide race.