" In such wars a posse comitatus marches ahead of the disciplined army. "

Posse comitatus \Pos"se com`i*ta"tus\ [L. posse to be able, to
have power + LL. comitatus a county, from comes, comitis, a
count. See County, and Power.]
1. (Law) The power of the county, or the citizens who may be
summoned by the sheriff to assist the authorities in
suppressing a riot, or executing any legal precept which
is forcibly opposed. --Blackstone.

2. A collection of people; a throng; a rabble. [Colloq.]

Note: The word comitatus is often omitted, and posse alone
used. ``A whole posse of enthusiasts.'' --Carlyle.

As if the passion that rules were the sheriff of
the place, and came off with all the posse.
--Locke.