These polls have not yet absorbed the fact that Santorum practically won Iowa. That will take a few days to sink in.
If many voters conclude that Santorum has a chance, and is a viable alternative to Gingrich, I believe they will shift to Santorum.
But we won’t know for a few days.
I believe you’re right about that absorption factor.
Santorum clearly won by losing by only eight! Hopefully, we can un-tie some of Romney’s backers IF we can ever convince them that we are going to keep his ceiling in the basement until we get our conservative candidate up and running!