Increased American casualties correlate 100% with election season.
100%
It is silly to ignore the facts -- that American initiatives contributed to the casualties. No one suggests that the enemy here cannot marshall their forces, although their ability to do so is limited. To blindly assume increased casualties are caused by the enemy's ability to increase our casualties at will shows ignorance of the simplest statistical analysis.
It was pretty clever how the Iraqis drew us into attacking Fallujah in November 2004, knowing that it was an election season. Look how they increased our casualties by marshalling their forces!