This Essay is intended for Congressional committee staff-whether employed by the committee or by members assigned to the committee-if they are called to review an administration legislative proposal to amend or repeal The Posse Comitatus Act ("The Act").2 It will be in two parts: background (to ensure that you and your members understand the statute's origins and implications); and separate Sections on expected issues and positions that will be asserted, or should be explored, as you prepare for testimony by supporters and opponents of the Bill.
Blackstone, in his Commentaries,3 describes posse comitatus (power of the community or county) as that portion of the (male) population above the age of fifteen which a sheriff could summon to his assistance in order to keep the peace. The term had its common law origins in the Middle Ages. Although the composition of the posse makes no class distinctions, it was, by virtue of the fact that members had to supply their own arms and armor,4 limited to members of the propertied class. It was from this pool that the militia was formed. Most, but not all, of the American colonies maintained a militia not only for defense from external threats but also to suppress domestic threats.5 It was in this context that Arthur St. Clair, Governor of the Northwest Territory, told Secretary of State Thomas Jefferson in June 1791, "every necessary aid either in suppressing tumults, apprehending offenders or safely keeping them after they are apprehended, to which of the Power of the County may be inadequate, will be cheerfully rendered by the military."6
Early in the nineteenth century the doctrine regulating the domestic use of the armed forces achieved its present contours. If the President called on the state militia or the army for law enforcement purposes, they would be utilized either to ensure the constitutional guarantee of a republican form of government to the states, or, as The Calling Forth Act of 1792 provided, to enforce federal law against "combinations too powerful to be suppressed by the ordinary course of judicial proceedings, or by the powers vested in the marshals."7 The Act provided, however, that "... whenever it may be necessary, in the judgment of the President, to use the militia force ... [he] shall forthwith, and previous thereto, by proclamation, command such insurgents to disperse, and retire peaceably to their respective abodes, within a limited time."8
In 1849, the Supreme Court clarified the President's constitutional authority to act in support of state governments in Luther v. Borden.9 Five years later, US Attorney General Caleb Cushing concluded that US Marshals could, without presidential authority, call forth the militia and army to enforce federal law:
A Marshall of the United States, when opposed in the execution of his duty, by unlawful combinations, has authority to summon the entire able-bodied force of his precinct, as a posse comitatus. This authority comprehends, not only bystanders and other citizens generally, but any and all organized armed force, whether militia of the State, or officers, soldiers, sailors, and marines of the United States.10
Cushing's definition overturned the traditional distinction between the military and the posse/militia, lumping the former with the latter, and including as well "bystanders and other citizens generally."11 The Cushing Doctrine, based on British precedent and utilized briefly to enforce the Fugitive Slave Laws, lay dormant until 1868 when Attorney General William W. Evarts extended it to permit local authorities in the former Confederacy to seek military assistance to suppress domestic violence.12
In 1878, Representative Knott of Kentucky proposed an amendment to the Army Appropriations Act which rejected the Cushing Doctrine; this amendment came to be known as the Posse Comitatus Act. It provided that
it shall not be lawful to employ any part of the Army of the United States, as a posse comitatus, or otherwise, for the purpose of executing the laws, except in such cases and under such circumstances as such employment of said force may be expressly authorized by the Constitution or by act of Congress. …