half-ass samurai 

a person in an important job , usually one affecting the life and death of the people around, who does so poorly at his job that the people around him suffer, often at the cost of their lives, similar to a samurai who did not take the shogunate seriously

proper usage> George W. Bush is a half-ass samurai

improper usage> He reads like a half-ass samurai

half-ass samurai by David Lukens March 18, 2008