“This passionate attachment to party, little known before the Civil War, had been forged by the Civil War itself. If was as if, in the cauldron of civil strife, every American had been melted down into one or the other of two elementary political particles, one Republican, the other Democrat. To its massed and devoted partisans the party was a church, whose creeds and slogans supplied men with their political principles, whose celebrations supplied them with their holiday outings. To its massed and devoted partisans the party was also a standing army perpetually arrayed for battle, an army whose orders men gladly obeyed, whose rudest tricks its partisans cheered, as patriots will cheer the night raids and ambushes of the nation’s fighting men.
Identifying themselves with a party, Americans looked on their chosen party as a kind of end in itself; its victories were their victories, its prosperity their prosperity. For themselves they asked little, for the identification with party was strong and passionate. In the Middle West in the 1880s, ‘the Republican Party,’ recalled the urban reformer Brand Whitlock, ‘was not a faction, not a group, not a wing, it was an institution … a synonym for patriotism, another name for the nation. One became, in Urbana and in Ohio for many years, a Republican just as the Eskimo dons fur clothes.’ If the Democrats’ supporters did not harbor such grandiose sentiments, their attachment to the Democracy was nonetheless deep, in part because the self-vaunting Republicans treated their party rivals with arrogant contempt.
from The Poltics of War: The Story of Two Wars Which Altered Forever the Political Life of the American Republic by Walter Karp