“For some reason...”
1. The media mercilessly played up Perry’s “gaffes” from the get-go; the media practically ignores (for now) Romney’s gaffes. (he made two this past week as bad as any of Perry’s).
2. It’s partly a money matter. Perry’s money is less than Romney’s and Perry’s SuperPac is small, and hence must spend it’s money on pro-Perry ads - not anti-Romney ads. Gingrich SuperPac is the only one spending on anti-Romney ads.
3. I really doubt that voters are forgetting that whole Bush/Texas/Governor/Air Force similarity thing.
I understand Perry had raised a lot of money. I do agree that the media hammered him.