FreeRepublic is far from monolithic, and not everyone who posts here is friendly. Just check out the first post when it says "in before the" and fill in the blank for whatever they are in before.
That poster is unique because he is also unofficially the biggest Bachmann booster here, and posting more threads on her than anyone. It doesn’t seem like he would want to also troll against Palin at the same time.
He seems to be using Bachmann’s, Rollins/Romney strategy of attacking Palin, who is Romney’s only real threat.
At the least he is pushing a war of sometype by being both her recognized chief promoter, and a chief anti-Palin troll at the same time.