OC will swing heavily toward Romney; they're the largest bastion of moderate Republicans left in the state.
That map is Tom Campbell's performance in the Republican primary for Senate. He received 17.36% of the vote in Orange County, falling well behind Carly Fiorina but also behind hard-right Chuck DeVore, an Orange County native. Orange County has always been a haven for far-right candidates and causes; in all the state, only Kern County rivals it in this respect.
Reps Royce (R-40) and Campbell III (R-48) are moderate Republicans (at least, compared to the rest of the national party).
Northern OC is far-right, the further south you go the more moderate it gets. Torie's precinct breakdown for Prop 8 highlighted it pretty clearly.