Given the alternative is Jerry Brown, she is the best the pack in CA has to offer...
Then let Jerry Brown win. In the long run, he'll do less damage to the GOP and California, and leave a lot more room for fixing and cleaning the mess than when Whitmans and Scharzeneggers make the messes and deliver near-mortal blows to the Republican party and conservatism on a level that Democrats and Liberals couldn't even begin to match.
I've already gone the path you advocate and voted for RINOs for the reason you cite. Arnold has taught me a valuable lesson. I am applying what I learned, and will urge others to do what I do: REFUSE TO VOTE FOR BIG GOVERNMENT REPUBLICANS because they are, in the long run, the bigger danger.