Santorum surged in December of 2011 last year, and reached his peak in February of 2012 (and I don't think the surged even seemed possible until it seemed clear Cain/Gingrich/Perry were all duds). If he's learned a lesson from his last go, it's that no candidate included in the debates can just be discounted.
I don't think he can do as well as in 2012, but after his 2012 performance he should be able to stay relevant, a part of the discussion, promoting his views, which is a significant victory in and of itself. Depending on how Tom Wolf's tenure goes, perhaps he can run for PA Gov in 2018 or 2022, build up relevancy, and then run again at some point in the mid-2020s; he's still only 56 years old and has time to do this sort of thing. Running in 2016 will keep his name in the news.
LOL at both of these possibilities. I assume neither of you guys have seen Santorum's favorability ratings in PA?
Has there actually been a recent poll taken on his favorability? All I was able to find was the exit poll from 2014, where only 23% of Pennsylvanians said he would make a good president, but that's a different question from favorability. PPP polled him in a Pennsylvania Republican presidential primary in June, he placed 8th with only 8% of the vote, ahead of only Ryan and Walker, and even trailing 'other', but again, that's a different question from favorability.
That being said, I'd be surprised if he's in or close to positive favorability in his home state.
For what it's worth, nationally Santorum isn't terrible - he's at 22/26 favorability as of July. It's interesting that a majority of the U.S. population don't have an opinion of him despite the fact that he almost won the republican nomination last time:
http://www.gallup.com/poll/173402/clinton-best-known-best-liked-potential-2016-candidate.aspx?ref=image
