I know it's long, but I cut lots of good stuff out. Couldn't bear to cut another word. Check out the entirety, widely available online.
"[Political parties] serve to organize faction, to give it an artificial and extraordinary force; to put, in the place of the delegated will of the nation the will of a party, often a small but artful and enterprising minority of the community.
"[T]hey are likely, in the course of time and things, to become potent engines, by which cunning, ambitious, and unprincipled men will be enabled to subvert the power of the people and to usurp for themselves the reins of government, destroying afterwards the very engines which have lifted them to unjust dominion.
"Let me now take a more comprehensive view, and warn you in the most solemn manner against the baneful effects of the spirit of party generally.
"The alternate domination of one faction over another, sharpened by the spirit of revenge, natural to party dissension... is itself a frightful despotism. But this leads at length to a more formal and permanent despotism. The disorders and miseries which result gradually incline the minds of men to seek security and repose in the absolute power of an individual; and sooner or later the chief of some prevailing faction, more able or more fortunate than his competitors, turns this disposition to the purposes of his own elevation, on the ruins of public liberty.
"The common and continual mischiefs of the spirit of party are sufficient to make it the interest and duty of a wise people to discourage and restrain it.
"It serves always to distract the public councils and enfeeble the public administration. It agitates the community with ill-founded jealousies and false alarms, kindles the animosity of one part against another, foments occasionally riot and insurrection. It opens the door to foreign influence and corruption, which finds a facilitated access to the government itself through the channels of party passions. Thus the policy and the will of one country are subjected to the policy and will of another. "
George Washington, Farewell Address 1796
