This is a super mashup of “tarred and feathered” (to excoriate or criticize someone in a humiliating and public manner) and “tarred (painted) with the same brush” (unfairly judge or categorize as being the same as someone, usually in a negative manner). Both idioms refer to a negative action against another. They also both have the word “tar” in them, which is probably the cause of the mental hiccup. Also, brushes can be composed of hairs, which may have led the mind back to the word “feather”. A big thanks to Michael Boyette for hearing this one and sending it to my Facebook page, Malaphors.