Let’s not forget the extremely pro-Romney nature of Katrina Trinko’s reporting for National Review.
The truth is that as people feel less pressured to vote for the leading anti-Romney, the more votes will go to the others. Santorum will surely pick up in the polls as Romney drops to his usual 20%. Ron Paul will stay at his 10%. Perry is gone. That leaves 70% to be divided between Newt Gingrich and Rick Santorum: Newt could win 49% and Rick would still beat Mitt.
Santorum can still do well enough to continue, and maybe earn the VP slot.
No one wants Santorum in the VP slot.