I mean, right before Sharon checks out, he (who has impeccable credentials for his strong military positions) says Likud is a dead end and seeks to start a middle ground party with key people from Labour.
How well is Netanyahu going to compete with the complete and utter bailout from his party that Sharon did... esp. considering how much of a hawk they both were? When one of the two hawks says the position is untenable, and he's the one who's actually been in wars and really knows what's involved, it has to make all moderate Israelis reconsider their support of Likud. Strongly, I'd think.