cannon fodder, meaning someone who is expendable or in simpler terms, a tool. It is a verry flexible term that is used widley in reference to politics and athletics, but most frequently in combat. The term is a military term that dates back to the civil war, troops would be sent out as distraction to the cannons, or simply as "food for the cannons" in other words, fodder means food, thus cannon fodder means cannon food.
1)Bush is Chenneys cannon fodder... what a tool.
2)in the game of rugby, Backs are Cannon fodder for the Forwards, who do all the real work
3)half of the platoon was used as cannon fodder when they went over the top of the trench.