In a funny way, he kept the coalition together, at least in part. And it was a coalition that could not otherwise stay together because of the particular make-up of the social conservative faction. They will never compromise, it's simply not in their make-up, and their standards are exceedingly high -- far beyond the reach of the remaining 85-90% of the population. So they sit at home (as many did in the '00 Presidential election) or they come out for their particular niche candidate -- as they did here.
I don't know if McClintock had this figured out in advance or not -- maybe he did. If he did, more power to him and may he have a great future.