As the cite to the Washington University Law Quarterly (above) makes very clear, the Posse Comitatus Act was originally a knee-jerk over-reaction to a specific situation right after the Civil War, and only applies to the Army (and the Air Force since it was originally part of the Army). The military wants nothing to do with law enforcement, the civilian law enforcement agencies don't want the help of the military, and nobody in their right mind wants this to change.