In the case of the lesser of two evils, chose the lesser based on other factors.
A Republican Governor might help the cause of pro-life indirectly by a re-districting plan that would help to bring more of a pro-life legislature to California.
On the other hand, if the Catholic felt that both were bad, then voting for Brown might be the chose, as Brown might help the poor more that Meg Whitman.
I am offended that Jerry Brown uses a picture of Mother Teresa on his campaign website, and he is very forcefully in favor of abortion -- at least that is what his website claims...