Just one thing to add...
I thought a little more about this and the first thing that popped into my head is that USC's opponent is Notre Dame. That in itself should get Sanchez's juices flowing along with the rest of USC' playmakers... at home, coliseum, national spotlight, TV game... you get the picture. To me that adds up to more than a 30 point margin of victory. That's because USC's pride is at stake. That's why they should put out the kind of effort it will take to smother ND thoroughly.
It's hard to figure what makes these guys tick. Man for man, they are the most talented team in the country. PC scoffs at the idea that style points matter and Sarkisian is no Norm Chow, that's for sure. But the ingredients are there for USC to dominate any team it wants to. I get the feeling that as long as they are out front and don't feel threatened, the players tend to lay back and just go through the motions without really stepping up and beating their man. That's the problem with betting USC. You never know when they will feel like playing up to their potential unless it's a big OOC game.
In addition to all that, Notre Dame's defense is terrible and I think a normal effort will be enough to whup them completely. If the Trojans are motivated, and I've explained why I think they will be, they should cover this number, possibly by halftime.