It's NEVER about principle with these people. They fight against the conservatives who are a THREAT. Palin and Gingrich were popular enough and effective enough with the public to present a threat to the ambitions of the Romney wing of the party. That's why they have always been made into targets and smeared.
Your right..guess they don’t consider Bachmann a threat and decided “Hey we can bring her out now and get the Conservative vote” they must really think we are stupid to buy that crap. My first choice was Palin, my 2nd choice was Gingrich, but the establishment wanted Romney so badly, didnt we hear constantly how it was “Romney’s turn” oh goodie goodie, we have Romney, let’s all jump for joy/sarc