> California elects republicans statewide all the time.
Well, California has an unusually large number of separately elected Statewide officers, but for the big three statewide offices (Governor and the two US Senators), "all the time" would be something of an exaggeration. In the last 19 years, Arnold Schwarzenegger's reelection as Governor is the only time a Republican has been elected to one of those big-3 statewide offices in a normal election.
> Arnold Schwarzenegger,
Arnold Schwarzenegger was first elected in a recall election which uses different procedures (an open plurality election with no primary to filter the field, with a side-by-side majority vote on the same ballot for actually recalling the incumbent -- more people voted for the incumbent Democrat to be retained than voted for the Republican Schwarzenegger to replace him.)
> Pete Wilson
Pete Wilson -- the last Republican elected Senator from or Governor of California, was last elected Governor 19 years ago. The political landscape has changed a bit since then.
> a Senator can win too.
Pete Wilson did it the last time 25 years ago. Sure, the Republicans could run a candidate that could win, but they haven't shown much propensity to do so.