He was tossed out on his arse because he deserved to be, that’s the begining middle and end of it. Believe me, this guy will be destroyed in a national election if he his the nominee.. He’s not politically savvy, intellectually astute, or personable enough to win what is going to be a nasty nasty race... he’ll at best get 45% of the vote, and more likely wind up with 40% or less.
If that's the criteria, and I disagree with your assessment of those as regards Santorum, we'll have trouble even if Gingrich can pull out of his slump and start winning again, because nobody has ever called Gingrich "personable", and he's proven just in the past two years that his sense of "politically savvy" isn't all it's cracked up to be.