[W]hat possible purpose does this lashing-out serve?....

“ [W]hat possible purpose does this lashing-out serve? Will activists be shamed into recovering their previous enthusiasm? Will Republicans stop their vicious attacks because Obama is lashing out to his left? It was pure self-indulgence; even if he feels aggrieved, he has to judge his words by their usefulness, not by his desire to vent. This isn't about him. ”

Paul Krugman