The way I understand it, the Republicans have already woken up, and are certainly not taken a Santorum win for granted.
The options they have are: just fight as hard as they can and hope for the best; or pull Santorum out. The latter option means that the Republicans can write-off a win at all, but they still get to keep Santorum as a popular figure with national name-recognition. A possible bid to take on Ed Rendell has already been floated on this forum.
You are quite right, but I don't think that Casey has an edge either.
No other candidate could beat Santorum (period).
Casey only wins if Santorum fails to sperate Casey from his father (period).
Santorum would win in a campaign that was dependent only on issues (period).
Casey is ahead right now because he is a Casey (period).
And, also, Santorum v Casey is going to be a national race in its scope. Only two people in PA have any expirience running a national campaign:
Rick Santorum and Arlen Specter.
I agree. Plus, a year and a half is a heck of a long time in politics. I'm not calling this one for either Santorum or Casey yet, but it'll definitely be a nail-biter for both sides concerned, and one to watch for everybody else.