You're in denial. Santorum was not in it to win it for him. His job was to help Romney.
Santorum never believed that he would get enough support to even come close to win. He was feeding off the dumbest of the party who easily forget that he called Romney "a real conservative" only a few years back, endorsed Arlen, and compared Mittens to Ronald Reagan in 2004.
He knew the only people that would support him would be those not informed OR Romney supporters ashamed to admit they support Romney so they join in on the Santorum scam.