Yglesias says yes:
Mitt Romney has serious liabilities in a GOP primary on paper that Tim Pawlenty and Rick Perry didn’t have. But in primary elections, gaffes and poor debate performances matter a lot. There are many more “swing voters” in a primary since the candidates are ideologically similar and voters/donors/etc. don’t have tribal allegiances that create high floors for the candidates.
Steve Benen traces it back to Perry's time in Texas. Bernstein isn't ruling Perry out yet:
It's basically between him and a guy who a whole lot of people in the party don't trust on core Republican issues, and Perry has still survived a decade in office with surprisingly little baggage that will bring veto attempts from key GOP actors. There are some things that would make them look twice, whether it's immigration or immunization or property rights (which I assume we'll hear about soon), but really: are any people who care passionately about abortion in the GOP going to choose Romney over Perry? Nope.
The Dish 