One pro-establishment type (Mr. Y) says of another (Mr. L): “the butt directs the brain”. The context was that Mr. L was appointed to be a government minister, and people are complaining that Mr. L cannot be trusted to act partially. Presumably Mr. Y is claiming that when Mr. L takes the position of a minister, he will act impartially as demanded by the position. Many people remain unconvinced.
Mr. Y, apparently, did not realize that the saying is derogatory. It implies that the person in question cannot think independently, and his behaviour will inevitably be biased by his position. No one will use it on one’s friend on purpose. What does that tell us when Mr. Y used it on Mr. L?
On the other hand, Mr. L is presently firmly pro-establishment. But he was, in the beginning of his political career, in the pan-democrat camp. That’s part of the reason he is the target of so much derision. Others question his qualification.
Such is the quality of some of the “leaders” of the pro-establishment camp.