The direct and intentional actions of the Republican party in California are in large part responsible for its in ability to break say 44-45% in most CA elections.
No it's the national party's fault for obsession over Jesus and what he would think about gay marriage and abortion. The state party, led by the Governator, understands how much the fundies are screwing his party.
With the exception of Arnold...the CA GOP has so much trouble because of the propositions of the early 90s (When Pete Wilson was in power...they basically stuck the middle finger at the state's hispanic population...which in any given state tends to give about 1/3rd...roughly...of its support to the GOP...well...it continues to bite them in the arse.)
Certainly the National GOP's tilt rightward hasn't helped...but it wasn't like the CA GOP was in good position before that happened.