For Newt to catch Romney, 3/4 of Santorum’s supporters would have to switch to Newt. For Santorum to catch Romney, 2/3 of Gingrich’s followers would have to switch. Both of the above numbers assume that none of the supporters would go to Romney. I cannot picture those numbers moving.
I might be tainted by the comments I have seen on FR, but I cannot picture, for example, people who call Santorum “Little Ricky”, “Father Ricky”, or “Romney Lite” switching their votes that way.
You’re tainted by what you’re seeing on FR. They’re on their own mission here, but don’t represent a large amount of the Newt supporters, IMO.