I have no doubt that Perry is sincere when he says he is a devout Christian but you do not organize a meeting in Reliant Stadium (football stadium for you Aggies

) as Governor without a political agenda. That is the reason that most of the invited political guests did not RSVP the event. There were cameras. There were people who might buy his book. There was an opportunity to be seen praying the loudest.
A preacher maybe, a revival maybe (lots of room to pass the plate), but not a politician that is probably going to be running for President.
It is what it is - but don't confuse the backlash as being anti-Christian just anti-phony-Christian.
Peace